can be used.
.PP
Each dhcpd.conf file must have one (and only one)
-\fIserver-identifier\fR declaration, which tells dhcpd the identifier
-to use when issuing leases. For every subnet which will be served,
-there must be one \fIsubnet\fR declaration, which tells dhcpd how to
-recognize that an address is on that subnet. A \fIsubnet\fR
-declaration is required for each subnet even if no addresses will be
-dynamically allocated on that subnet.
+.I server-identifier
+declaration, which tells dhcpd the identifier to use when issuing
+leases. For every subnet which will be served, and for every subnet
+to which the dhcp server is connected, there must be one \fIsubnet\fR
+declaration, which tells dhcpd how to recognize that an address is on
+that subnet. A \fIsubnet\fR declaration is required for each subnet
+even if no addresses will be dynamically allocated on that subnet.
.PP
Some installations have physical networks on which more than one IP
subnet operates. For example, if there is a site-wide requirement
netmask, are sufficient to determine whether any given IP address is
on the specified subnet.
.PP
+Although a netmask must be given with every subnet declaration, it is
+recommended that if there is any variance in subnet masks at a site, a
+subnet-mask option statement be used in each subnet declaration to set
+the desired subnet mask, since any subnet-mask option statement will
+override the subnet mask declared in the subnet statement.
+.PP
.B The
.I range
.B statement
\fBoption subnet-mask\fR \fIip-address\fR\fB;\fR
.PP
The subnet mask option specifies the client's subnet mask as per RFC
-950.
+950. If no subnet mask option is provided anywhere in scope, as a
+last resort dhcpd will use the subnet mask from the subnet declaration
+for the network on which an address is being assigned. However,
+.I any
+subnet-mask option declaration that is in scope for the address being
+assigned will override the subnet mask specified in the subnet
+declaration.
.PP
\fBoption time-offset\fR \fIint32\fR\fB;\fR
.PP
Each dhcpd.conf file must have one (and only one) _\bs_\be_\br_\bv_\be_\br_\b-
_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br declaration, which tells dhcpd the identifier
- to use when issuing leases. For every subnet which will
- be served, there must be one _\bs_\bu_\bb_\bn_\be_\bt declaration, which
- tells dhcpd how to recognize that an address is on that
+ to use when issuing leases. For every subnet which will
+ be served, and for every subnet to which the dhcp server
+ is connected, there must be one _\bs_\bu_\bb_\bn_\be_\bt declaration, which
+ tells dhcpd how to recognize that an address is on that
subnet. A _\bs_\bu_\bb_\bn_\be_\bt declaration is required for each subnet
even if no addresses will be dynamically allocated on that
subnet.
- Some installations have physical networks on which more
dhcpd.conf(5) dhcpd.conf(5)
- than one IP subnet operates. For example, if there is a
+ Some installations have physical networks on which more
+ than one IP subnet operates. For example, if there is a
site-wide requirement that 8-bit subnet masks be used, but
- a department with a single physical ethernet network
- expands to the point where it has more than 254 nodes, it
+ a department with a single physical ethernet network
+ expands to the point where it has more than 254 nodes, it
may be necessary to run two 8-bit subnets on the same eth-
- ernet until such time as a new physical network can be
- added. In this case, the _\bs_\bu_\bb_\bn_\be_\bt declarations for these
- two networks may be enclosed in a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk declara-
+ ernet until such time as a new physical network can be
+ added. In this case, the _\bs_\bu_\bb_\bn_\be_\bt declarations for these
+ two networks may be enclosed in a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk declara-
tion.
Some sites may have departments which have clients on more
- than one subnet, but it may be desirable to offer those
- clients a uniform set of parameters which are different
- than what would be offered to clients from other depart-
- ments on the same subnet. For clients which will be
+ than one subnet, but it may be desirable to offer those
+ clients a uniform set of parameters which are different
+ than what would be offered to clients from other depart-
+ ments on the same subnet. For clients which will be
declared explicitly with _\bh_\bo_\bs_\bt declarations, these declara-
- tions can be enclosed in a _\bg_\br_\bo_\bu_\bp declaration along with
- the parameters which are common to that department. For
- clients whose addresses will be dynamically assigned,
- there is currently no way to group parameter assignments
+ tions can be enclosed in a _\bg_\br_\bo_\bu_\bp declaration along with
+ the parameters which are common to that department. For
+ clients whose addresses will be dynamically assigned,
+ there is currently no way to group parameter assignments
other than by network topology.
- When a client is to be booted, its boot parameters are
+ When a client is to be booted, its boot parameters are
determined by first consulting that client's _\bh_\bo_\bs_\bt declara-
- tion (if any), then consulting the _\bg_\br_\bo_\bu_\bp declaration (if
+ tion (if any), then consulting the _\bg_\br_\bo_\bu_\bp declaration (if
any) which enclosed that _\bh_\bo_\bs_\bt declaration, then consulting
- the _\bs_\bu_\bb_\bn_\be_\bt declaration for the subnet on which the client
+ the _\bs_\bu_\bb_\bn_\be_\bt declaration for the subnet on which the client
is booting, then consulting the _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk declaration
- (if any) containing that subnet, and finally consulting
+ (if any) containing that subnet, and finally consulting
the top-level parameters which may be specified outside of
any declaration.
- When dhcpd tries to find a _\bh_\bo_\bs_\bt declaration for a client,
- it first looks for a _\bh_\bo_\bs_\bt declaration which has a _\bf_\bi_\bx_\be_\bd_\b-
- _\ba_\bd_\bd_\br_\be_\bs_\bs parameter which matches the subnet or shared net-
- work on which the client is booting. If it doesn't find
- any such entry, it then tries to find an entry which has
- no _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs parameter. If no such entry is found,
- then dhcpd acts as if there is no entry in the dhcpd.conf
- file for that client, even if there is an entry for that
+ When dhcpd tries to find a _\bh_\bo_\bs_\bt declaration for a client,
+ it first looks for a _\bh_\bo_\bs_\bt declaration which has a _\bf_\bi_\bx_\be_\bd_\b-
+ _\ba_\bd_\bd_\br_\be_\bs_\bs parameter which matches the subnet or shared net-
+ work on which the client is booting. If it doesn't find
+ any such entry, it then tries to find an entry which has
+ no _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs parameter. If no such entry is found,
+ then dhcpd acts as if there is no entry in the dhcpd.conf
+ file for that client, even if there is an entry for that
client on a different subnet or shared network.
E\bEX\bXA\bAM\bMP\bPL\bLE\bES\bS
subnet 204.254.239.0 netmask 255.255.255.224 {
_\bs_\bu_\bb_\bn_\be_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs_\b._\b._\b.
range 204.254.239.10 204.254.239.30;
- }
dhcpd.conf(5) dhcpd.conf(5)
+ }
subnet 204.254.239.32 netmask 255.255.255.224 {
_\bs_\bu_\bb_\bn_\be_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs_\b._\b._\b.
range 204.254.239.42 204.254.239.62;
Figure 1
- Notice that after the server-identifier declaration,
- there's a place for global parameters. These might be
- things like the organization's domain name, the addresses
- of the name servers (if they are common to the entire
+ Notice that after the server-identifier declaration,
+ there's a place for global parameters. These might be
+ things like the organization's domain name, the addresses
+ of the name servers (if they are common to the entire
organization), and so on. So, for example:
option domain-name "isc.org";
Figure 2
- As you can see in Figure 2, it's legal to specify host
- addresses in parameters as domain names rather than as
- numeric IP addresses. If a given hostname resolves to
- more than one IP address (for example, if that host has
- two ethernet interfaces), both addresses are supplied to
+ As you can see in Figure 2, it's legal to specify host
+ addresses in parameters as domain names rather than as
+ numeric IP addresses. If a given hostname resolves to
+ more than one IP address (for example, if that host has
+ two ethernet interfaces), both addresses are supplied to
the client.
- In Figure 1, you can see that both the shared-network
- statement and the subnet statements can have parameters.
- Let us say that the shared network _\bI_\bS_\bC_\b-_\bB_\bI_\bG_\bG_\bI_\bE supports an
- entire department - perhaps the accounting department.
- If accounting has its own domain, then a shared-network-
+ In Figure 1, you can see that both the shared-network
+ statement and the subnet statements can have parameters.
+ Let us say that the shared network _\bI_\bS_\bC_\b-_\bB_\bI_\bG_\bG_\bI_\bE supports an
+ entire department - perhaps the accounting department.
+ If accounting has its own domain, then a shared-network-
specific parameter might be:
option domain-name "accounting.isc.org";
-
3
dhcpd.conf(5) dhcpd.conf(5)
- All subnet declarations appearing in the shared-network
- declaration would then have the domain-name option set to
+ All subnet declarations appearing in the shared-network
+ declaration would then have the domain-name option set to
"accounting.isc.org" instead of just "isc.org".
The most obvious reason for having subnet-specific parame-
- ters as shown in Figure 1 is that each subnet, of neces-
- sity, has its own router. So for the first subnet, for
+ ters as shown in Figure 1 is that each subnet, of neces-
+ sity, has its own router. So for the first subnet, for
example, there should be something like:
option routers 204.254.239.1;
- Note that the address here is specified numerically.
+ Note that the address here is specified numerically.
This is not required - if you have a different domain name
- for each interface on your router, it's perfectly legiti-
- mate to use the domain name for that interface instead of
+ for each interface on your router, it's perfectly legiti-
+ mate to use the domain name for that interface instead of
the numeric address. However, in many cases there may be
- only one domain name for all of a router's IP addresses,
+ only one domain name for all of a router's IP addresses,
and it would not be appropriate to use that name here.
- In Figure 1 there is also a _\bg_\br_\bo_\bu_\bp statement, which pro-
- vides common parameters for a set of three hosts - zappo,
- beppo and harpo. As you can see, these hosts are all in
- the test.isc.org domain, so it might make sense for a
- group-specific parameter to override the domain name sup-
+ In Figure 1 there is also a _\bg_\br_\bo_\bu_\bp statement, which pro-
+ vides common parameters for a set of three hosts - zappo,
+ beppo and harpo. As you can see, these hosts are all in
+ the test.isc.org domain, so it might make sense for a
+ group-specific parameter to override the domain name sup-
plied to these hosts:
option domain-name "test.isc.org";
Also, given the domain they're in, these are probably test
- machines. If we wanted to test the DHCP leasing mecha-
+ machines. If we wanted to test the DHCP leasing mecha-
nism, we might set the lease timeout somewhat shorter than
the default:
default-lease-time 120;
You may have noticed that while some parameters start with
- the _\bo_\bp_\bt_\bi_\bo_\bn keyword, some do not. Parameters starting
+ the _\bo_\bp_\bt_\bi_\bo_\bn keyword, some do not. Parameters starting
with the _\bo_\bp_\bt_\bi_\bo_\bn keyword correspond to actual DHCP options,
while parameters that do not start with the option keyword
either control the behaviour of the DHCP server (e.g., how
- long a lease dhcpd will give out), or specify client
+ long a lease dhcpd will give out), or specify client
parameters that are not optional in the DHCP protocol (for
example, server-name and filename).
- In Figure 1, each host had _\bh_\bo_\bs_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs.
- These could include such things as the _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option,
- the name of a file to upload (the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\b) _\ba_\bn_\bd
- _\bt_\bh_\be _\ba_\bd_\bd_\br_\be_\bs_\bs _\bo_\bf _\bt_\bh_\be _\bs_\be_\br_\bv_\be_\br _\bf_\br_\bo_\bm _\bw_\bh_\bi_\bc_\bh _\bt_\bo _\bu_\bp_\bl_\bo_\ba_\bd _\bt_\bh_\be _\bf_\bi_\bl_\be
- _\b(_\bt_\bh_\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter). In general, any parameter
- can appear anywhere that parameters are allowed, and will
- be applied according to the scope in which the parameter
+ In Figure 1, each host had _\bh_\bo_\bs_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs.
+ These could include such things as the _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option,
+ the name of a file to upload (the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\b) _\ba_\bn_\bd
+ _\bt_\bh_\be _\ba_\bd_\bd_\br_\be_\bs_\bs _\bo_\bf _\bt_\bh_\be _\bs_\be_\br_\bv_\be_\br _\bf_\br_\bo_\bm _\bw_\bh_\bi_\bc_\bh _\bt_\bo _\bu_\bp_\bl_\bo_\ba_\bd _\bt_\bh_\be _\bf_\bi_\bl_\be
+ _\b(_\bt_\bh_\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter). In general, any parameter
+ can appear anywhere that parameters are allowed, and will
+ be applied according to the scope in which the parameter
appears.
dhcpd.conf(5) dhcpd.conf(5)
- Imagine that you have a site with a lot of NCD X-
- Terminals. These terminals come in a variety of models,
- and you want to specify the boot files for each models.
- One way to do this would be to have host declarations for
+ Imagine that you have a site with a lot of NCD X-
+ Terminals. These terminals come in a variety of models,
+ and you want to specify the boot files for each models.
+ One way to do this would be to have host declarations for
each server and group them by model:
group {
s\bse\ber\brv\bve\ber\br-\b-i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be;\b;
- The server-identifier declaration must be used exactly
+ The server-identifier declaration must be used exactly
once in each dhcpd.conf file to tell dhcpd what IP address
- to use as its server identifier, as required by the DHCP
- protocol. On a machine with a single interface, the
- server identifier should be the primary address of that
- interface. On machines with multiple interfaces, the
- address of one such interface must be chosen. Any
+ to use as its server identifier, as required by the DHCP
+ protocol. On a machine with a single interface, the
+ server identifier should be the primary address of that
+ interface. On machines with multiple interfaces, the
+ address of one such interface must be chosen. Any
address may be chosen, as long as it is the address of one
of the interfaces of that machine.
dhcpd.conf(5) dhcpd.conf(5)
- The _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement is used to inform the DHCP
+ The _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement is used to inform the DHCP
server that some IP subnets actually share the same physi-
- cal network. Any subnets in a shared network should be
- declared within a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement. Parameters
- specified in the _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement will be used
- when booting clients on those subnets unless parameters
- provided at the subnet or host level override them. If
+ cal network. Any subnets in a shared network should be
+ declared within a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement. Parameters
+ specified in the _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement will be used
+ when booting clients on those subnets unless parameters
+ provided at the subnet or host level override them. If
any subnet in a shared network has addresses available for
- dynamic allocation, those addresses are collected into a
- common pool for that shared network and assigned to
- clients as needed. There is no way to distinguish on
+ dynamic allocation, those addresses are collected into a
+ common pool for that shared network and assigned to
+ clients as needed. There is no way to distinguish on
which subnet of a shared network a client should boot.
_\bN_\ba_\bm_\be should be the name of the shared network. This name
- is used when printing debugging messages, so it should be
- descriptive for the shared network. The name may have
- the syntax of a valid domain name (although it will never
- be used as such), or it may be any arbitrary name,
+ is used when printing debugging messages, so it should be
+ descriptive for the shared network. The name may have
+ the syntax of a valid domain name (although it will never
+ be used as such), or it may be any arbitrary name,
enclosed in quotes.
T\bTh\bhe\be _\bs_\bu_\bb_\bn_\be_\bt s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
[ _\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn_\bs ]
}\b}
- The _\bs_\bu_\bb_\bn_\be_\bt statement is used to provide dhcpd with enough
- information to tell whether or not an IP address is on
- that subnet. It may also be used to provide subnet-
- specific parameters and to specify what addresses may be
- dynamically allocated to clients booting on that subnet.
- Such addresses are specified using the _\br_\ba_\bn_\bg_\be declaration.
+ The _\bs_\bu_\bb_\bn_\be_\bt statement is used to provide dhcpd with enough
+ information to tell whether or not an IP address is on
+ that subnet. It may also be used to provide subnet-
+ specific parameters and to specify what addresses may be
+ dynamically allocated to clients booting on that subnet.
+ Such addresses are specified using the _\br_\ba_\bn_\bg_\be declaration.
- The _\bs_\bu_\bb_\bn_\be_\bt_\b-_\bn_\bu_\bm_\bb_\be_\br should be an IP address or domain name
- which resolves to the subnet number of the subnet being
+ The _\bs_\bu_\bb_\bn_\be_\bt_\b-_\bn_\bu_\bm_\bb_\be_\br should be an IP address or domain name
+ which resolves to the subnet number of the subnet being
described. The _\bn_\be_\bt_\bm_\ba_\bs_\bk should be an IP address or domain
name which resolves to the subnet mask of the subnet being
described. The subnet number, together with the netmask,
- are sufficient to determine whether any given IP address
+ are sufficient to determine whether any given IP address
is on the specified subnet.
+ Although a netmask must be given with every subnet decla-
+ ration, it is recommended that if there is any variance in
+ subnet masks at a site, a subnet-mask option statement be
+ used in each subnet declaration to set the desired subnet
+ mask, since any subnet-mask option statement will override
+ the subnet mask declared in the subnet statement.
+
T\bTh\bhe\be _\br_\ba_\bn_\bg_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
r\bra\ban\bng\bge\be [ d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp ] _\bl_\bo_\bw_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [ _\bh_\bi_\bg_\bh_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs];\b;
- For any subnet on which addresses will be assigned dynami-
- cally, there must be at least one _\br_\ba_\bn_\bg_\be statement. The
- range statement gives the lowest and highest IP addresses
- in a range. All IP addresses in the range should be in
- the subnet in which the _\br_\ba_\bn_\bg_\be statement is declared. The
- _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp flag may be specified if addresses in the
- specified range may be dynamically assigned to BOOTP
- clients as well as DHCP clients. When specifying a
+ For any subnet on which addresses will be assigned
dhcpd.conf(5) dhcpd.conf(5)
- single address, _\bh_\bi_\bg_\bh_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs can be omitted.
+ dynamically, there must be at least one _\br_\ba_\bn_\bg_\be statement.
+ The range statement gives the lowest and highest IP
+ addresses in a range. All IP addresses in the range
+ should be in the subnet in which the _\br_\ba_\bn_\bg_\be statement is
+ declared. The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp flag may be specified if
+ addresses in the specified range may be dynamically
+ assigned to BOOTP clients as well as DHCP clients. When
+ specifying a single address, _\bh_\bi_\bg_\bh_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs can be omitted.
T\bTh\bhe\be _\bh_\bo_\bs_\bt s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
[ _\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn_\bs ]
}\b}
- There must be at least one h\bho\bos\bst\bt statement for every BOOTP
- client that is to be served. h\bho\bos\bst\bt statements may also be
- specified for DHCP clients, although this is not required
+ There must be at least one h\bho\bos\bst\bt statement for every BOOTP
+ client that is to be served. h\bho\bos\bst\bt statements may also be
+ specified for DHCP clients, although this is not required
unless booting is only enabled for known hosts.
- If it is desirable to be able to boot a DHCP or BOOTP
- client on more than one subnet with fixed addresses, more
- than one address may be specified in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
- parameter, or more than one h\bho\bos\bst\bt statement may be speci-
+ If it is desirable to be able to boot a DHCP or BOOTP
+ client on more than one subnet with fixed addresses, more
+ than one address may be specified in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ parameter, or more than one h\bho\bos\bst\bt statement may be speci-
fied.
- If client-specific boot parameters must change based on
+ If client-specific boot parameters must change based on
the network to which the client is attached, then multiple
h\bho\bos\bst\bt statements should be used.
- If a client is to be booted using a fixed address if it's
+ If a client is to be booted using a fixed address if it's
possible, but should be allocated a dynamic address other-
- wise, then a h\bho\bos\bst\bt statement must be specified without a
+ wise, then a h\bho\bos\bst\bt statement must be specified without a
f\bfi\bix\bxe\bed\bd-\b-a\bad\bdd\bdr\bre\bes\bss\bs clause. _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be should be a name identify-
- ing the host. If a _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option is not specified for
+ ing the host. If a _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option is not specified for
the host, _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be is used.
- _\bH_\bo_\bs_\bt declarations are matched to actual DHCP or BOOTP
+ _\bH_\bo_\bs_\bt declarations are matched to actual DHCP or BOOTP
clients by matching the dhcp-client-identifier option
- specified in the _\bh_\bo_\bs_\bt declaration to the one supplied by
+ specified in the _\bh_\bo_\bs_\bt declaration to the one supplied by
the client, or, if the _\bh_\bo_\bs_\bt declaration or the client does
- not provide a dhcp-client-identifier option, by matching
+ not provide a dhcp-client-identifier option, by matching
the _\bh_\ba_\br_\bd_\bw_\ba_\br_\be parameter in the _\bh_\bo_\bs_\bt declaration to the net-
- work hardware address supplied by the client. BOOTP
- clients do not normally provide a _\bd_\bh_\bc_\bp_\b-_\bc_\bl_\bi_\be_\bn_\bt_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br,
- so the hardware address must be used for all clients that
+ work hardware address supplied by the client. BOOTP
+ clients do not normally provide a _\bd_\bh_\bc_\bp_\b-_\bc_\bl_\bi_\be_\bn_\bt_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br,
+ so the hardware address must be used for all clients that
may boot using the BOOTP protocol.
T\bTh\bhe\be _\bg_\br_\bo_\bu_\bp s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
g\bgr\bro\bou\bup\bp {
[ _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs ]
[ _\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn_\bs ]
- }\b}
-
- The group statement is used simply to apply one or more
- parameters to a group of declarations. It can be used to
- group hosts, shared networks, subnets, or even other
- groups.
-
dhcpd.conf(5) dhcpd.conf(5)
+ }\b}
+
+ The group statement is used simply to apply one or more
+ parameters to a group of declarations. It can be used to
+ group hosts, shared networks, subnets, or even other
+ groups.
+
R\bRE\bEF\bFE\bER\bRE\bEN\bNC\bCE\bE:\b: P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS
T\bTh\bhe\be _\bd_\be_\bf_\ba_\bu_\bl_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bt_\bi_\bm_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
m\bma\bax\bx-\b-l\ble\bea\bas\bse\be-\b-t\bti\bim\bme\be _\bt_\bi_\bm_\be;\b;
- _\bT_\bi_\bm_\be should be the maximum length in seconds that will be
- assigned to a lease if the client requesting the lease
+ _\bT_\bi_\bm_\be should be the maximum length in seconds that will be
+ assigned to a lease if the client requesting the lease
asks for a specific expiration time.
T\bTh\bhe\be _\bh_\ba_\br_\bd_\bw_\ba_\br_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
h\bha\bar\brd\bdw\bwa\bar\bre\be _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\bt_\by_\bp_\be _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- In order for a BOOTP client to be recognized, its network
- hardware address must be declared using a _\bh_\ba_\br_\bd_\bw_\ba_\br_\be clause
- in the _\bh_\bo_\bs_\bt statement. _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\bt_\by_\bp_\be must be the name of
- a physical hardware interface type. Currently, only the
- e\bet\bth\bhe\ber\brn\bne\bet\bt type is recognized, although support for t\bto\bok\bke\ben\bn-\b-
+ In order for a BOOTP client to be recognized, its network
+ hardware address must be declared using a _\bh_\ba_\br_\bd_\bw_\ba_\br_\be clause
+ in the _\bh_\bo_\bs_\bt statement. _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\bt_\by_\bp_\be must be the name of
+ a physical hardware interface type. Currently, only the
+ e\bet\bth\bhe\ber\brn\bne\bet\bt type is recognized, although support for t\bto\bok\bke\ben\bn-\b-
r\bri\bin\bng\bg and f\bfd\bdd\bdi\bi hardware types would also be desirable. The
- _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs should be a set of hexadecimal octets
- (numbers from 0 through ff) seperated by colons. The
+ _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs should be a set of hexadecimal octets
+ (numbers from 0 through ff) seperated by colons. The
_\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\bf_\bR _\bs_\bt_\ba_\bt_\be_\bm_\be_\bn_\bt _\bm_\ba_\by _\ba_\bl_\bs_\bo _\bb_\be _\bu_\bs_\be_\bd _\bf_\bo_\br _\bD_\bH_\bC_\bP _\bc_\bl_\bi_\be_\bn_\bt_\bs_\b.
T\bTh\bhe\be _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
f\bfi\bil\ble\ben\bna\bam\bme\be "\b"_\bf_\bi_\bl_\be_\bn_\ba_\bm_\be"\b";\b;
- The _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement can be used to specify the name of
- the initial boot file which is to be loaded by a client.
+ The _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement can be used to specify the name of
+ the initial boot file which is to be loaded by a client.
The _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be should be a filename recognizable to whatever
- file transfer protocol the client can be expected to use
+ file transfer protocol the client can be expected to use
to load the file.
T\bTh\bhe\be _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
The _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be statement can be used to inform the client
of the name of the server from which it is booting. _\bN_\ba_\bm_\be
- should be the name that will be provided to the client.
- T\bTh\bhe\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
- n\bne\bex\bxt\bt-\b-s\bse\ber\brv\bve\ber\br _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be;\b;
- The _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br statement is used to specify the host
+ 8
- 8
+dhcpd.conf(5) dhcpd.conf(5)
+ should be the name that will be provided to the client.
-dhcpd.conf(5) dhcpd.conf(5)
+ T\bTh\bhe\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
+ n\bne\bex\bxt\bt-\b-s\bse\ber\brv\bve\ber\br _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be;\b;
- address of the server from which the initial boot file
- (specified in the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement) is to be loaded.
- _\bS_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be should be a numeric IP address or a domain
- name. If no _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter applies to a given
- client, the address specified in the _\bs_\be_\br_\bv_\be_\br_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br
+ The _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br statement is used to specify the host
+ address of the server from which the initial boot file
+ (specified in the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement) is to be loaded.
+ _\bS_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be should be a numeric IP address or a domain
+ name. If no _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter applies to a given
+ client, the address specified in the _\bs_\be_\br_\bv_\be_\br_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br
statement is used.
T\bTh\bhe\be _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
f\bfi\bix\bxe\bed\bd-\b-a\bad\bdd\bdr\bre\bes\bss\bs _\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs statement is used to assign one or more
- fixed IP addresses to a client. It should only appear in
+ The _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs statement is used to assign one or more
+ fixed IP addresses to a client. It should only appear in
a _\bh_\bo_\bs_\bt declaration. If more than one address is supplied,
- then when the client boots, it will be assigned the
- address which corresponds to the network on which it is
- booting. If none of the addresses in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
- statement are on the network on which the client is boot-
- ing, that client will not match the _\bh_\bo_\bs_\bt declaration con-
+ then when the client boots, it will be assigned the
+ address which corresponds to the network on which it is
+ booting. If none of the addresses in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ statement are on the network on which the client is boot-
+ ing, that client will not match the _\bh_\bo_\bs_\bt declaration con-
taining that _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs statement. Each _\ba_\bd_\bd_\br_\be_\bs_\bs should
be either an IP address or a domain name which resolves to
one or more IP addresses.
d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp-\b-l\ble\bea\bas\bse\be-\b-c\bcu\but\bto\bof\bff\bf _\bd_\ba_\bt_\be;\b;
- The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bc_\bu_\bt_\bo_\bf_\bf statement sets the ending
+ The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bc_\bu_\bt_\bo_\bf_\bf statement sets the ending
time for all leases assigned dynamically to BOOTP clients.
- Because BOOTP clients do not have any way of renewing
- leases, and don't know that their leases could expire, by
+ Because BOOTP clients do not have any way of renewing
+ leases, and don't know that their leases could expire, by
default dhcpd assignes infinite leases to all BOOTP
clients. However, it may make sense in some situations to
- set a cutoff date for all BOOTP leases - for example, the
+ set a cutoff date for all BOOTP leases - for example, the
end of a school term, or the time at night when a facility
is closed and all machines are required to be powered off.
W YYYY/MM/DD HH:MM:SS
- W is the day of the week expressed as a number from zero
- (Sunday) to six (Saturday). YYYY is the year, including
+ W is the day of the week expressed as a number from zero
+ (Sunday) to six (Saturday). YYYY is the year, including
the century. MM is the month expressed as a number from 1
- to 12. DD is the day of the month, counting from 1. HH
- is the hour, from zero to 23. MM is the minute and SS is
- the second. The time is always in Greenwich Mean Time
- (GMT), not local time.
+ to 12. DD is the day of the month, counting from 1. HH
+ is the hour, from zero to 23. MM is the minute and SS is
- T\bTh\bhe\be _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
- d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp-\b-l\ble\bea\bas\bse\be-\b-l\ble\ben\bng\bgt\bth\bh _\bl_\be_\bn_\bg_\bt_\bh;\b;
+ 9
- 9
+dhcpd.conf(5) dhcpd.conf(5)
+ the second. The time is always in Greenwich Mean Time
+ (GMT), not local time.
-dhcpd.conf(5) dhcpd.conf(5)
+ T\bTh\bhe\be _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
+ d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp-\b-l\ble\bea\bas\bse\be-\b-l\ble\ben\bng\bgt\bth\bh _\bl_\be_\bn_\bg_\bt_\bh;\b;
- The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh statement is used to set
- the length of leases dynamically assigned to BOOTP
- clients. At some sites, it may be possible to assume
- that a lease is no longer in use if its holder has not
- used BOOTP or DHCP to get its address within a certain
+ The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh statement is used to set
+ the length of leases dynamically assigned to BOOTP
+ clients. At some sites, it may be possible to assume
+ that a lease is no longer in use if its holder has not
+ used BOOTP or DHCP to get its address within a certain
time period. The period is specified in _\bl_\be_\bn_\bg_\bt_\bh as a num-
- ber of seconds. If a client reboots using BOOTP during
+ ber of seconds. If a client reboots using BOOTP during
the timeout period, the lease duration is reset to _\bl_\be_\bn_\bg_\bt_\bh,
- so a BOOTP client that boots frequently enough will never
+ so a BOOTP client that boots frequently enough will never
lose its lease. Needless to say, this parameter should be
adjusted with extreme caution.
b\bbo\boo\bot\bt-\b-u\bun\bnk\bkn\bno\bow\bwn\bn-\b-c\bcl\bli\bie\ben\bnt\bts\bs _\bf_\bl_\ba_\bg;\b;
- The _\bb_\bo_\bo_\bt_\b-_\bu_\bn_\bk_\bn_\bo_\bw_\bn_\b-_\bc_\bl_\bi_\be_\bn_\bt_\bs statement is used to tell dhcpd
- whether or not to dynamically assign addresses to unknown
+ The _\bb_\bo_\bo_\bt_\b-_\bu_\bn_\bk_\bn_\bo_\bw_\bn_\b-_\bc_\bl_\bi_\be_\bn_\bt_\bs statement is used to tell dhcpd
+ whether or not to dynamically assign addresses to unknown
DHCP clients. If _\bf_\bl_\ba_\bg is true (the default), then
addresses are dynamically assigned to unknown DHCP clients
when available. If _\bf_\bl_\ba_\bg is false, then addresses are pro-
- vided only to DHCP clients which match at least one host
+ vided only to DHCP clients which match at least one host
declaration.
T\bTh\bhe\be _\bg_\be_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be_\bs s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
g\bge\bet\bt-\b-l\ble\bea\bas\bse\be-\b-h\bho\bos\bst\btn\bna\bam\bme\bes\bs _\bf_\bl_\ba_\bg;\b;
- The _\bg_\be_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be_\bs statement is used to tell dhcpd
+ The _\bg_\be_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be_\bs statement is used to tell dhcpd
whether or not to look up the domain name corresponding to
- the IP address of each address in the lease pool and use
- that address for the DHCP _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option. If _\bf_\bl_\ba_\bg is
- true, then this lookup is done for all addresses in the
- current scope. By default, or if _\bf_\bl_\ba_\bg is false, no
+ the IP address of each address in the lease pool and use
+ that address for the DHCP _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option. If _\bf_\bl_\ba_\bg is
+ true, then this lookup is done for all addresses in the
+ current scope. By default, or if _\bf_\bl_\ba_\bg is false, no
lookups are done.
R\bRE\bEF\bFE\bER\bRE\bEN\bNC\bCE\bE:\b: O\bOP\bPT\bTI\bIO\bON\bN S\bST\bTA\bAT\bTE\bEM\bME\bEN\bNT\bTS\bS
- DHCP _\bo_\bp_\bt_\bi_\bo_\bn statements always start with the _\bo_\bp_\bt_\bi_\bo_\bn key-
+ DHCP _\bo_\bp_\bt_\bi_\bo_\bn statements always start with the _\bo_\bp_\bt_\bi_\bo_\bn key-
word, followed by an option name, followed by option data.
- The option names and data formats are described below.
- It is not necessary to exhaustively specify all DHCP
- options - only those options which are needed by clients
+ The option names and data formats are described below.
+ It is not necessary to exhaustively specify all DHCP
+ options - only those options which are needed by clients
must be specified.
- Option data comes in a variety of formats, as defined
+ Option data comes in a variety of formats, as defined
below:
- The i\bip\bp-\b-a\bad\bdd\bdr\bre\bes\bss\bs data type can be entered either as an
- explicit IP address (e.g., 239.254.197.10) or as a domain
- name (e.g., haagen.isc.org). When entering a domain name,
- be sure that that domain name resolves to a single IP
- address.
-
- The i\bin\bnt\bt3\b32\b2 data type specifies a signed 32-bit integer.
dhcpd.conf(5) dhcpd.conf(5)
+ The i\bip\bp-\b-a\bad\bdd\bdr\bre\bes\bss\bs data type can be entered either as an
+ explicit IP address (e.g., 239.254.197.10) or as a domain
+ name (e.g., haagen.isc.org). When entering a domain name,
+ be sure that that domain name resolves to a single IP
+ address.
+
+ The i\bin\bnt\bt3\b32\b2 data type specifies a signed 32-bit integer.
The u\bui\bin\bnt\bt3\b32\b2 data type specifies an unsigned 32-bit integer.
The i\bin\bnt\bt1\b16\b6 and u\bui\bin\bnt\bt1\b16\b6 data types specify signed and
- unsigned 16-bit integers. The i\bin\bnt\bt8\b8 and u\bui\bin\bnt\bt8\b8 data types
- specify signed and unsigned 8-bit integers. Unsigned
+ unsigned 16-bit integers. The i\bin\bnt\bt8\b8 and u\bui\bin\bnt\bt8\b8 data types
+ specify signed and unsigned 8-bit integers. Unsigned
8-bit integers are also sometimes referred to as octets.
- The s\bst\btr\bri\bin\bng\bg data type specifies an NVT ASCII string, which
- must be enclosed in double quotes - for example, to spec-
+ The s\bst\btr\bri\bin\bng\bg data type specifies an NVT ASCII string, which
+ must be enclosed in double quotes - for example, to spec-
ify a domain-name option, the syntax would be
option domain-name "isc.org";
- The f\bfl\bla\bag\bg data type specifies a boolean value. Booleans
- can be either true or false (or on or off, if that makes
+ The f\bfl\bla\bag\bg data type specifies a boolean value. Booleans
+ can be either true or false (or on or off, if that makes
more sense to you).
- The d\bda\bat\bta\ba-\b-s\bst\btr\bri\bin\bng\bg data type specifies either an NVT ASCII
- string enclosed in double quotes, or a series of octets
+ The d\bda\bat\bta\ba-\b-s\bst\btr\bri\bin\bng\bg data type specifies either an NVT ASCII
+ string enclosed in double quotes, or a series of octets
specified in hexadecimal, seperated by colons. For exam-
ple:
or
option client-identifier 43:4c:49:45:54:2d:46:4f:4f;
- The documentation for the various options mentioned below
- is taken from the latest IETF draft document on DHCP
- options. Options which are not listed by name may be
- defined by the name option-_\bn_\bn_\bn, where _\bn_\bn_\bn _\bi_\bs _\bt_\bh_\be _\bd_\be_\bc_\bi_\bm_\ba_\bl
+ The documentation for the various options mentioned below
+ is taken from the latest IETF draft document on DHCP
+ options. Options which are not listed by name may be
+ defined by the name option-_\bn_\bn_\bn, where _\bn_\bn_\bn _\bi_\bs _\bt_\bh_\be _\bd_\be_\bc_\bi_\bm_\ba_\bl
_\bn_\bu_\bm_\bb_\be_\br _\bo_\bf _\bt_\bh_\be _\bo_\bp_\bt_\bi_\bo_\bn _\bc_\bo_\bd_\be_\b. _\bT_\bh_\be_\bs_\be _\bo_\bp_\bt_\bi_\bo_\bn_\bs _\bm_\ba_\by _\bb_\be _\bf_\bo_\bl_\bl_\bo_\bw_\be_\bd
- _\be_\bi_\bt_\bh_\be_\br _\bb_\by _\ba _\bs_\bt_\br_\bi_\bn_\bg_\b, _\be_\bn_\bc_\bl_\bo_\bs_\be_\bd _\bi_\bn _\bq_\bu_\bo_\bt_\be_\bs_\b, _\bo_\br _\bb_\by _\ba _\bs_\be_\br_\bi_\be_\bs _\bo_\bf
- _\bo_\bc_\bt_\be_\bt_\bs_\b, _\be_\bx_\bp_\br_\be_\bs_\bs_\be_\bd _\ba_\bs _\bt_\bw_\bo_\b-_\bd_\bi_\bg_\bi_\bt _\bh_\be_\bx_\ba_\bd_\be_\bc_\bi_\bm_\ba_\bl _\bn_\bu_\bm_\bb_\be_\br_\bs _\bs_\be_\bp_\be_\br_\b-
+ _\be_\bi_\bt_\bh_\be_\br _\bb_\by _\ba _\bs_\bt_\br_\bi_\bn_\bg_\b, _\be_\bn_\bc_\bl_\bo_\bs_\be_\bd _\bi_\bn _\bq_\bu_\bo_\bt_\be_\bs_\b, _\bo_\br _\bb_\by _\ba _\bs_\be_\br_\bi_\be_\bs _\bo_\bf
+ _\bo_\bc_\bt_\be_\bt_\bs_\b, _\be_\bx_\bp_\br_\be_\bs_\bs_\be_\bd _\ba_\bs _\bt_\bw_\bo_\b-_\bd_\bi_\bg_\bi_\bt _\bh_\be_\bx_\ba_\bd_\be_\bc_\bi_\bm_\ba_\bl _\bn_\bu_\bm_\bb_\be_\br_\bs _\bs_\be_\bp_\be_\br_\b-
_\ba_\bt_\be_\bd _\bb_\by _\bc_\bo_\bl_\bo_\bn_\bs_\b. _\bF_\bo_\br _\be_\bx_\ba_\bm_\bp_\bl_\be_\b:
option option-133 "my-option-133-text";
option option-129 1:54:c9:2b:47;
- Because dhcpd does not know the format of these undefined
- option codes, no checking is done to ensure the correct-
+ Because dhcpd does not know the format of these undefined
+ option codes, no checking is done to ensure the correct-
ness of the entered data.
The standard options are:
o\bop\bpt\bti\bio\bon\bn s\bsu\bub\bbn\bne\bet\bt-\b-m\bma\bas\bsk\bk _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- The subnet mask option specifies the client's subnet mask
- as per RFC 950.
+ The subnet mask option specifies the client's subnet mask
+ as per RFC 950. If no subnet mask option is provided
- o\bop\bpt\bti\bio\bon\bn t\bti\bim\bme\be-\b-o\bof\bff\bfs\bse\bet\bt _\bi_\bn_\bt_\b3_\b2;\b;
- The time-offset option specifies the offset of the
- client's subnet in seconds from Coordinated Universal Time
- (UTC).
+ 11
- 11
+dhcpd.conf(5) dhcpd.conf(5)
+ anywhere in scope, as a last resort dhcpd will use the
+ subnet mask from the subnet declaration for the network on
+ which an address is being assigned. However, _\ba_\bn_\by subnet-
+ mask option declaration that is in scope for the address
+ being assigned will override the subnet mask specified in
+ the subnet declaration.
-dhcpd.conf(5) dhcpd.conf(5)
+ o\bop\bpt\bti\bio\bon\bn t\bti\bim\bme\be-\b-o\bof\bff\bfs\bse\bet\bt _\bi_\bn_\bt_\b3_\b2;\b;
+ The time-offset option specifies the offset of the
+ client's subnet in seconds from Coordinated Universal Time
+ (UTC).
o\bop\bpt\bti\bio\bon\bn r\bro\bou\but\bte\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The routers option specifies a list of IP addresses for
- routers on the client's subnet. Routers should be listed
+ The routers option specifies a list of IP addresses for
+ routers on the client's subnet. Routers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn t\bti\bim\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\b[_\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The time-server option specifies a list of RFC 868 time
+ The time-server option specifies a list of RFC 868 time
servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];
- The name-servers option specifies a list of IEN 116 name
+ The name-servers option specifies a list of IEN 116 name
servers available to the client. Servers should be listed
in order of preference.
- o\bop\bpt\bti\bio\bon\bn d\bdo\bom\bma\bai\bin\bn-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
+ o\bop\bpt\bti\bio\bon\bn d\bdo\bom\bma\bai\bin\bn-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
];\b;
- The domain-name-servers option specifies a list of Domain
- Name System (STD 13, RFC 1035) name servers available to
- the client. Servers should be listed in order of prefer-
+ The domain-name-servers option specifies a list of Domain
+ Name System (STD 13, RFC 1035) name servers available to
+ the client. Servers should be listed in order of prefer-
ence.
o\bop\bpt\bti\bio\bon\bn l\blo\bog\bg-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The log-server option specifies a list of MIT-LCS UDP log
+ The log-server option specifies a list of MIT-LCS UDP log
servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn c\bco\boo\bok\bki\bie\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The cookie server option specifies a list of RFC 865
+ The cookie server option specifies a list of RFC 865
cookie servers available to the client. Servers should be
listed in order of preference.
o\bop\bpt\bti\bio\bon\bn l\blp\bpr\br-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The LPR server option specifies a list of RFC 1179 line
- printer servers available to the client. Servers should
- be listed in order of preference.
+ The LPR server option specifies a list of RFC 1179 line
- o\bop\bpt\bti\bio\bon\bn i\bim\bmp\bpr\bre\bes\bss\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The impress-server option specifies a list of Imagen
- Impress servers available to the client. Servers should
- be listed in order of preference.
- o\bop\bpt\bti\bio\bon\bn r\bre\bes\bso\bou\bur\brc\bce\be-\b-l\blo\boc\bca\bat\bti\bio\bon\bn-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
- ... ];\b;
+ 12
- This option specifies a list of RFC 887 Resource Location
- 12
+dhcpd.conf(5) dhcpd.conf(5)
+ printer servers available to the client. Servers should
+ be listed in order of preference.
+ o\bop\bpt\bti\bio\bon\bn i\bim\bmp\bpr\bre\bes\bss\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
-dhcpd.conf(5) dhcpd.conf(5)
+ The impress-server option specifies a list of Imagen
+ Impress servers available to the client. Servers should
+ be listed in order of preference.
+ o\bop\bpt\bti\bio\bon\bn r\bre\bes\bso\bou\bur\brc\bce\be-\b-l\blo\boc\bca\bat\bti\bio\bon\bn-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ ... ];\b;
+ This option specifies a list of RFC 887 Resource Location
servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn h\bho\bos\bst\bt-\b-n\bna\bam\bme\be _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the name of the client. The name
+ This option specifies the name of the client. The name
may or may not be qualified with the local domain name (it
is preferable to use the domain-name option to specify the
- domain name). See RFC 1035 for character set restric-
+ domain name). See RFC 1035 for character set restric-
tions.
o\bop\bpt\bti\bio\bon\bn b\bbo\boo\bot\bt-\b-s\bsi\biz\bze\be _\bu_\bi_\bn_\bt_\b1_\b6;\b;
- This option specifies the length in 512-octet blocks of
+ This option specifies the length in 512-octet blocks of
the default boot image for the client.
o\bop\bpt\bti\bio\bon\bn m\bme\ber\bri\bit\bt-\b-d\bdu\bum\bmp\bp _\bs_\bt_\br_\bi_\bn_\bg;\b;
This option specifies the path-name of a file to which the
- client's core image should be dumped in the event the
- client crashes. The path is formatted as a character
+ client's core image should be dumped in the event the
+ client crashes. The path is formatted as a character
string consisting of characters from the NVT ASCII charac-
ter set.
o\bop\bpt\bti\bio\bon\bn d\bdo\bom\bma\bai\bin\bn-\b-n\bna\bam\bme\be _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the domain name that client should
+ This option specifies the domain name that client should
use when resolving hostnames via the Domain Name System.
o\bop\bpt\bti\bio\bon\bn s\bsw\bwa\bap\bp-\b-s\bse\ber\brv\bve\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
o\bop\bpt\bti\bio\bon\bn r\bro\boo\bot\bt-\b-p\bpa\bat\bth\bh _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the path-name that contains the
- client's root disk. The path is formatted as a character
+ This option specifies the path-name that contains the
+ client's root disk. The path is formatted as a character
string consisting of characters from the NVT ASCII charac-
ter set.
o\bop\bpt\bti\bio\bon\bn i\bip\bp-\b-f\bfo\bor\brw\bwa\bar\brd\bdi\bin\bng\bg _\bf_\bl_\ba_\bg;\b;
- This option specifies whether the client should configure
- its IP layer for packet forwarding. A value of 0 means
- disable IP forwarding, and a value of 1 means enable IP
- forwarding.
-
- o\bop\bpt\bti\bio\bon\bn n\bno\bon\bn-\b-l\blo\boc\bca\bal\bl-\b-s\bso\bou\bur\brc\bce\be-\b-r\bro\bou\but\bti\bin\bng\bg _\bf_\bl_\ba_\bg;\b;
-
- This option specifies whether the client should configure
- its IP layer to allow forwarding of datagrams with non-
- local source routes (see Section 3.3.5 of [4] for a dis-
- cussion of this topic). A value of 0 means disallow for-
- warding of such datagrams, and a value of 1 means allow
-
13
dhcpd.conf(5) dhcpd.conf(5)
+ This option specifies whether the client should configure
+ its IP layer for packet forwarding. A value of 0 means
+ disable IP forwarding, and a value of 1 means enable IP
forwarding.
- o\bop\bpt\bti\bio\bon\bn p\bpo\bol\bli\bic\bcy\by-\b-f\bfi\bil\blt\bte\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ o\bop\bpt\bti\bio\bon\bn n\bno\bon\bn-\b-l\blo\boc\bca\bal\bl-\b-s\bso\bou\bur\brc\bce\be-\b-r\bro\bou\but\bti\bin\bng\bg _\bf_\bl_\ba_\bg;\b;
+
+ This option specifies whether the client should configure
+ its IP layer to allow forwarding of datagrams with non-
+ local source routes (see Section 3.3.5 of [4] for a dis-
+ cussion of this topic). A value of 0 means disallow for-
+ warding of such datagrams, and a value of 1 means allow
+ forwarding.
+
+ o\bop\bpt\bti\bio\bon\bn p\bpo\bol\bli\bic\bcy\by-\b-f\bfi\bil\blt\bte\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
_\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies policy filters for non-local source
- routing. The filters consist of a list of IP addresses
- and masks which specify destination/mask pairs with which
+ This option specifies policy filters for non-local source
+ routing. The filters consist of a list of IP addresses
+ and masks which specify destination/mask pairs with which
to filter incoming source routes.
Any source routed datagram whose next-hop address does not
- match one of the filters should be discarded by the
+ match one of the filters should be discarded by the
client.
See STD 3 (RFC1122) for further information.
o\bop\bpt\bti\bio\bon\bn m\bma\bax\bx-\b-d\bdg\bgr\bra\bam\bm-\b-r\bre\bea\bas\bss\bse\bem\bmb\bbl\bly\by _\bu_\bi_\bn_\bt_\b1_\b6;\b;
- This option specifies the maximum size datagram that the
- client should be prepared to reassemble. The minimum
+ This option specifies the maximum size datagram that the
+ client should be prepared to reassemble. The minimum
value legal value is 576.
o\bop\bpt\bti\bio\bon\bn d\bde\bef\bfa\bau\bul\blt\bt-\b-i\bip\bp-\b-t\btt\btl\bl _\bu_\bi_\bn_\bt_\b8_\b;
- This option specifies the default time-to-live that the
+ This option specifies the default time-to-live that the
client should use on outgoing datagrams.
o\bop\bpt\bti\bio\bon\bn p\bpa\bat\bth\bh-\b-m\bmt\btu\bu-\b-a\bag\bgi\bin\bng\bg-\b-t\bti\bim\bme\beo\bou\but\bt _\bu_\bi_\bn_\bt_\b3_\b2;\b;
This option specifies the timeout (in seconds) to use when
- aging Path MTU values discovered by the mechanism defined
+ aging Path MTU values discovered by the mechanism defined
in RFC 1191.
o\bop\bpt\bti\bio\bon\bn p\bpa\bat\bth\bh-\b-m\bmt\btu\bu-\b-p\bpl\bla\bat\bte\bea\bau\bu-\b-t\bta\bab\bbl\ble\be _\bu_\bi_\bn_\bt_\b1_\b6 [,\b, _\bu_\bi_\bn_\bt_\b1_\b6 ... ];\b;
- This option specifies a table of MTU sizes to use when
+ This option specifies a table of MTU sizes to use when
performing Path MTU Discovery as defined in RFC 1191. The
- table is formatted as a list of 16-bit unsigned integers,
- ordered from smallest to largest. The minimum MTU value
+ table is formatted as a list of 16-bit unsigned integers,
+ ordered from smallest to largest. The minimum MTU value
cannot be smaller than 68.
o\bop\bpt\bti\bio\bon\bn i\bin\bnt\bte\ber\brf\bfa\bac\bce\be-\b-m\bmt\btu\bu _\bu_\bi_\bn_\bt_\b1_\b6;\b;
- This option specifies the MTU to use on this interface.
- The minimum legal value for the MTU is 68.
-
- o\bop\bpt\bti\bio\bon\bn a\bal\bll\bl-\b-s\bsu\bub\bbn\bne\bet\bts\bs-\b-l\blo\boc\bca\bal\bl _\bf_\bl_\ba_\bg;\b;
-
- This option specifies whether or not the client may assume
- that all subnets of the IP network to which the client is
- connected use the same MTU as the subnet of that network
- to which the client is directly connected. A value of 1
- indicates that all subnets share the same MTU. A value of
- 0 means that the client should assume that some subnets of
-
14
dhcpd.conf(5) dhcpd.conf(5)
+ This option specifies the MTU to use on this interface.
+ The minimum legal value for the MTU is 68.
+
+ o\bop\bpt\bti\bio\bon\bn a\bal\bll\bl-\b-s\bsu\bub\bbn\bne\bet\bts\bs-\b-l\blo\boc\bca\bal\bl _\bf_\bl_\ba_\bg;\b;
+
+ This option specifies whether or not the client may assume
+ that all subnets of the IP network to which the client is
+ connected use the same MTU as the subnet of that network
+ to which the client is directly connected. A value of 1
+ indicates that all subnets share the same MTU. A value of
+ 0 means that the client should assume that some subnets of
the directly connected network may have smaller MTUs.
o\bop\bpt\bti\bio\bon\bn b\bbr\bro\boa\bad\bdc\bca\bas\bst\bt-\b-a\bad\bdd\bdr\bre\bes\bss\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- This option specifies the broadcast address in use on the
+ This option specifies the broadcast address in use on the
client's subnet. Legal values for broadcast addresses are
specified in section 3.2.1.3 of STD 3 (RFC1122).
o\bop\bpt\bti\bio\bon\bn p\bpe\ber\brf\bfo\bor\brm\bm-\b-m\bma\bas\bsk\bk-\b-d\bdi\bis\bsc\bco\bov\bve\ber\bry\by _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
- perform subnet mask discovery using ICMP. A value of 0
- indicates that the client should not perform mask discov-
- ery. A value of 1 means that the client should perform
+ This option specifies whether or not the client should
+ perform subnet mask discovery using ICMP. A value of 0
+ indicates that the client should not perform mask discov-
+ ery. A value of 1 means that the client should perform
mask discovery.
o\bop\bpt\bti\bio\bon\bn m\bma\bas\bsk\bk-\b-s\bsu\bup\bpp\bpl\bli\bie\ber\br _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
- respond to subnet mask requests using ICMP. A value of 0
- indicates that the client should not respond. A value of
+ This option specifies whether or not the client should
+ respond to subnet mask requests using ICMP. A value of 0
+ indicates that the client should not respond. A value of
1 means that the client should respond.
o\bop\bpt\bti\bio\bon\bn r\bro\bou\but\bte\ber\br-\b-d\bdi\bis\bsc\bco\bov\bve\ber\bry\by _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
+ This option specifies whether or not the client should
solicit routers using the Router Discovery mechanism
- defined in RFC 1256. A value of 0 indicates that the
- client should not perform router discovery. A value of 1
+ defined in RFC 1256. A value of 0 indicates that the
+ client should not perform router discovery. A value of 1
means that the client should perform router discovery.
o\bop\bpt\bti\bio\bon\bn r\bro\bou\but\bte\ber\br-\b-s\bso\bol\bli\bic\bci\bit\bta\bat\bti\bio\bon\bn-\b-a\bad\bdd\bdr\bre\bes\bss\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- This option specifies the address to which the client
+ This option specifies the address to which the client
should transmit router solicitation requests.
- o\bop\bpt\bti\bio\bon\bn s\bst\bta\bat\bti\bic\bc-\b-r\bro\bou\but\bte\bes\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ o\bop\bpt\bti\bio\bon\bn s\bst\bta\bat\bti\bic\bc-\b-r\bro\bou\but\bte\bes\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
_\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of static routes that the
- client should install in its routing cache. If multiple
- routes to the same destination are specified, they are
+ This option specifies a list of static routes that the
+ client should install in its routing cache. If multiple
+ routes to the same destination are specified, they are
listed in descending order of priority.
- The routes consist of a list of IP address pairs. The
- first address is the destination address, and the second
- address is the router for the destination.
-
- The default route (0.0.0.0) is an illegal destination for
- a static route. To specify the default route, use the
- r\bro\bou\but\bte\ber\brs\bs option.
- o\bop\bpt\bti\bio\bon\bn t\btr\bra\bai\bil\ble\ber\br-\b-e\ben\bnc\bca\bap\bps\bsu\bul\bla\bat\bti\bio\bon\bn _\bf_\bl_\ba_\bg;\b;
+ 15
- 15
+dhcpd.conf(5) dhcpd.conf(5)
+ The routes consist of a list of IP address pairs. The
+ first address is the destination address, and the second
+ address is the router for the destination.
-dhcpd.conf(5) dhcpd.conf(5)
+ The default route (0.0.0.0) is an illegal destination for
+ a static route. To specify the default route, use the
+ r\bro\bou\but\bte\ber\brs\bs option.
+ o\bop\bpt\bti\bio\bon\bn t\btr\bra\bai\bil\ble\ber\br-\b-e\ben\bnc\bca\bap\bps\bsu\bul\bla\bat\bti\bio\bon\bn _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
- negotiate the use of trailers (RFC 893 [14]) when using
- the ARP protocol. A value of 0 indicates that the client
- should not attempt to use trailers. A value of 1 means
+ This option specifies whether or not the client should
+ negotiate the use of trailers (RFC 893 [14]) when using
+ the ARP protocol. A value of 0 indicates that the client
+ should not attempt to use trailers. A value of 1 means
that the client should attempt to use trailers.
o\bop\bpt\bti\bio\bon\bn a\bar\brp\bp-\b-c\bca\bac\bch\bhe\be-\b-t\bti\bim\bme\beo\bou\but\bt _\bu_\bi_\bn_\bt_\b3_\b2;\b;
o\bop\bpt\bti\bio\bon\bn i\bie\bee\bee\be8\b80\b02\b2-\b-3\b3-\b-e\ben\bnc\bca\bap\bps\bsu\bul\bla\bat\bti\bio\bon\bn _\bf_\bl_\ba_\bg;\b;
This option specifies whether or not the client should use
- Ethernet Version 2 (RFC 894) or IEEE 802.3 (RFC 1042)
+ Ethernet Version 2 (RFC 894) or IEEE 802.3 (RFC 1042)
encapsulation if the interface is an Ethernet. A value of
- 0 indicates that the client should use RFC 894 encapsula-
- tion. A value of 1 means that the client should use RFC
+ 0 indicates that the client should use RFC 894 encapsula-
+ tion. A value of 1 means that the client should use RFC
1042 encapsulation.
o\bop\bpt\bti\bio\bon\bn d\bde\bef\bfa\bau\bul\blt\bt-\b-t\btc\bcp\bp-\b-t\btt\btl\bl _\bu_\bi_\bn_\bt_\b8;\b;
- This option specifies the default TTL that the client
- should use when sending TCP segments. The minimum value
+ This option specifies the default TTL that the client
+ should use when sending TCP segments. The minimum value
is 1.
o\bop\bpt\bti\bio\bon\bn t\btc\bcp\bp-\b-k\bke\bee\bep\bpa\bal\bli\biv\bve\be-\b-i\bin\bnt\bte\ber\brv\bva\bal\bl _\bu_\bi_\bn_\bt_\b3_\b2;\b;
- This option specifies the interval (in seconds) that the
- client TCP should wait before sending a keepalive message
- on a TCP connection. The time is specified as a 32-bit
- unsigned integer. A value of zero indicates that the
- client should not generate keepalive messages on connec-
+ This option specifies the interval (in seconds) that the
+ client TCP should wait before sending a keepalive message
+ on a TCP connection. The time is specified as a 32-bit
+ unsigned integer. A value of zero indicates that the
+ client should not generate keepalive messages on connec-
tions unless specifically requested by an application.
o\bop\bpt\bti\bio\bon\bn t\btc\bcp\bp-\b-k\bke\bee\bep\bpa\bal\bli\biv\bve\be-\b-g\bga\bar\brb\bba\bag\bge\be _\bf_\bl_\ba_\bg;\b;
This option specifies the whether or not the client should
- send TCP keepalive messages with a octet of garbage for
- compatibility with older implementations. A value of 0
+ send TCP keepalive messages with a octet of garbage for
+ compatibility with older implementations. A value of 0
indicates that a garbage octet should not be sent. A value
of 1 indicates that a garbage octet should be sent.
o\bop\bpt\bti\bio\bon\bn n\bni\bis\bs-\b-d\bdo\bom\bma\bai\bin\bn _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the name of the client's NIS (Sun
- Network Information Services) domain. The domain is for-
- matted as a character string consisting of characters from
- the NVT ASCII character set.
-
- o\bop\bpt\bti\bio\bon\bn n\bni\bis\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
-
- This option specifies a list of IP addresses indicating
- NIS servers available to the client. Servers should be
-
16
dhcpd.conf(5) dhcpd.conf(5)
+ This option specifies the name of the client's NIS (Sun
+ Network Information Services) domain. The domain is for-
+ matted as a character string consisting of characters from
+ the NVT ASCII character set.
+
+ o\bop\bpt\bti\bio\bon\bn n\bni\bis\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
+
+ This option specifies a list of IP addresses indicating
+ NIS servers available to the client. Servers should be
listed in order of preference.
o\bop\bpt\bti\bio\bon\bn n\bnt\btp\bp-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of IP addresses indicating
- NTP (RFC 1035) servers available to the client. Servers
+ This option specifies a list of IP addresses indicating
+ NTP (RFC 1035) servers available to the client. Servers
should be listed in order of preference.
- o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
+ o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
];\b;
- The NetBIOS name server (NBNS) option specifies a list of
+ The NetBIOS name server (NBNS) option specifies a list of
RFC 1001/1002 NBNS name servers listed in order of prefer-
ence.
o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-d\bdd\bd-\b-s\bse\ber\brv\bve\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The NetBIOS datagram distribution server (NBDD) option
- specifies a list of RFC 1001/1002 NBDD servers listed in
+ The NetBIOS datagram distribution server (NBDD) option
+ specifies a list of RFC 1001/1002 NBDD servers listed in
order of preference.
o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-n\bno\bod\bde\be-\b-t\bty\byp\bpe\be _\bu_\bi_\bn_\bt_\b8;\b;
- The NetBIOS node type option allows NetBIOS over TCP/IP
- clients which are configurable to be configured as
- described in RFC 1001/1002. The value is specified as a
+ The NetBIOS node type option allows NetBIOS over TCP/IP
+ clients which are configurable to be configured as
+ described in RFC 1001/1002. The value is specified as a
single octet which identifies the client type. A value of
- 1 corresponds to a NetBIOS B-node; a value of 2 corre-
+ 1 corresponds to a NetBIOS B-node; a value of 2 corre-
sponds to a P-node; a value of 4 corresponds to an M-node;
a value of 8 corresponds to an H-node.
The NetBIOS scope option specifies the NetBIOS over TCP/IP
scope parameter for the client as specified in RFC
- 1001/1002. See RFC1001, RFC1002, and RFC1035 for charac-
+ 1001/1002. See RFC1001, RFC1002, and RFC1035 for charac-
ter-set restrictions.
o\bop\bpt\bti\bio\bon\bn f\bfo\bon\bnt\bt-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of X Window System Font
- servers available to the client. Servers should be listed
+ This option specifies a list of X Window System Font
+ servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn x\bx-\b-d\bdi\bis\bsp\bpl\bla\bay\by-\b-m\bma\ban\bna\bag\bge\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of systems that are running
- the X Window System Display Manager and are available to
- the client. Addresses should be listed in order of pref-
- erence.
-
- o\bop\bpt\bti\bio\bon\bn d\bdh\bhc\bcp\bp-\b-c\bcl\bli\bie\ben\bnt\bt-\b-i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br _\bd_\ba_\bt_\ba_\b-_\bs_\bt_\br_\bi_\bn_\bg;\b;
-
- This option can be used to specify the a DHCP client
-
17
dhcpd.conf(5) dhcpd.conf(5)
- identifier in a host declaration, so that dhcpd can find
- the host record by matching against the client identifier.
+ This option specifies a list of systems that are running
+ the X Window System Display Manager and are available to
+ the client. Addresses should be listed in order of pref-
+ erence.
+
+ o\bop\bpt\bti\bio\bon\bn d\bdh\bhc\bcp\bp-\b-c\bcl\bli\bie\ben\bnt\bt-\b-i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br _\bd_\ba_\bt_\ba_\b-_\bs_\bt_\br_\bi_\bn_\bg;\b;
+
+ This option can be used to specify the a DHCP client iden-
+ tifier in a host declaration, so that dhcpd can find the
+ host record by matching against the client identifier.
S\bSE\bEE\bE A\bAL\bLS\bSO\bO
dhcpd.conf(5), dhcpd.leases(5), draft-ietf-dhc-
-
-
-
-
-
-
-
-
can be used.
.PP
Each dhcpd.conf file must have one (and only one)
-\fIserver-identifier\fR declaration, which tells dhcpd the identifier
-to use when issuing leases. For every subnet which will be served,
-there must be one \fIsubnet\fR declaration, which tells dhcpd how to
-recognize that an address is on that subnet. A \fIsubnet\fR
-declaration is required for each subnet even if no addresses will be
-dynamically allocated on that subnet.
+.I server-identifier
+declaration, which tells dhcpd the identifier to use when issuing
+leases. For every subnet which will be served, and for every subnet
+to which the dhcp server is connected, there must be one \fIsubnet\fR
+declaration, which tells dhcpd how to recognize that an address is on
+that subnet. A \fIsubnet\fR declaration is required for each subnet
+even if no addresses will be dynamically allocated on that subnet.
.PP
Some installations have physical networks on which more than one IP
subnet operates. For example, if there is a site-wide requirement
netmask, are sufficient to determine whether any given IP address is
on the specified subnet.
.PP
+Although a netmask must be given with every subnet declaration, it is
+recommended that if there is any variance in subnet masks at a site, a
+subnet-mask option statement be used in each subnet declaration to set
+the desired subnet mask, since any subnet-mask option statement will
+override the subnet mask declared in the subnet statement.
+.PP
.B The
.I range
.B statement
\fBoption subnet-mask\fR \fIip-address\fR\fB;\fR
.PP
The subnet mask option specifies the client's subnet mask as per RFC
-950.
+950. If no subnet mask option is provided anywhere in scope, as a
+last resort dhcpd will use the subnet mask from the subnet declaration
+for the network on which an address is being assigned. However,
+.I any
+subnet-mask option declaration that is in scope for the address being
+assigned will override the subnet mask specified in the subnet
+declaration.
.PP
\fBoption time-offset\fR \fIint32\fR\fB;\fR
.PP
Each dhcpd.conf file must have one (and only one) _\bs_\be_\br_\bv_\be_\br_\b-
_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br declaration, which tells dhcpd the identifier
- to use when issuing leases. For every subnet which will
- be served, there must be one _\bs_\bu_\bb_\bn_\be_\bt declaration, which
- tells dhcpd how to recognize that an address is on that
+ to use when issuing leases. For every subnet which will
+ be served, and for every subnet to which the dhcp server
+ is connected, there must be one _\bs_\bu_\bb_\bn_\be_\bt declaration, which
+ tells dhcpd how to recognize that an address is on that
subnet. A _\bs_\bu_\bb_\bn_\be_\bt declaration is required for each subnet
even if no addresses will be dynamically allocated on that
subnet.
- Some installations have physical networks on which more
dhcpd.conf(5) dhcpd.conf(5)
- than one IP subnet operates. For example, if there is a
+ Some installations have physical networks on which more
+ than one IP subnet operates. For example, if there is a
site-wide requirement that 8-bit subnet masks be used, but
- a department with a single physical ethernet network
- expands to the point where it has more than 254 nodes, it
+ a department with a single physical ethernet network
+ expands to the point where it has more than 254 nodes, it
may be necessary to run two 8-bit subnets on the same eth-
- ernet until such time as a new physical network can be
- added. In this case, the _\bs_\bu_\bb_\bn_\be_\bt declarations for these
- two networks may be enclosed in a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk declara-
+ ernet until such time as a new physical network can be
+ added. In this case, the _\bs_\bu_\bb_\bn_\be_\bt declarations for these
+ two networks may be enclosed in a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk declara-
tion.
Some sites may have departments which have clients on more
- than one subnet, but it may be desirable to offer those
- clients a uniform set of parameters which are different
- than what would be offered to clients from other depart-
- ments on the same subnet. For clients which will be
+ than one subnet, but it may be desirable to offer those
+ clients a uniform set of parameters which are different
+ than what would be offered to clients from other depart-
+ ments on the same subnet. For clients which will be
declared explicitly with _\bh_\bo_\bs_\bt declarations, these declara-
- tions can be enclosed in a _\bg_\br_\bo_\bu_\bp declaration along with
- the parameters which are common to that department. For
- clients whose addresses will be dynamically assigned,
- there is currently no way to group parameter assignments
+ tions can be enclosed in a _\bg_\br_\bo_\bu_\bp declaration along with
+ the parameters which are common to that department. For
+ clients whose addresses will be dynamically assigned,
+ there is currently no way to group parameter assignments
other than by network topology.
- When a client is to be booted, its boot parameters are
+ When a client is to be booted, its boot parameters are
determined by first consulting that client's _\bh_\bo_\bs_\bt declara-
- tion (if any), then consulting the _\bg_\br_\bo_\bu_\bp declaration (if
+ tion (if any), then consulting the _\bg_\br_\bo_\bu_\bp declaration (if
any) which enclosed that _\bh_\bo_\bs_\bt declaration, then consulting
- the _\bs_\bu_\bb_\bn_\be_\bt declaration for the subnet on which the client
+ the _\bs_\bu_\bb_\bn_\be_\bt declaration for the subnet on which the client
is booting, then consulting the _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk declaration
- (if any) containing that subnet, and finally consulting
+ (if any) containing that subnet, and finally consulting
the top-level parameters which may be specified outside of
any declaration.
- When dhcpd tries to find a _\bh_\bo_\bs_\bt declaration for a client,
- it first looks for a _\bh_\bo_\bs_\bt declaration which has a _\bf_\bi_\bx_\be_\bd_\b-
- _\ba_\bd_\bd_\br_\be_\bs_\bs parameter which matches the subnet or shared net-
- work on which the client is booting. If it doesn't find
- any such entry, it then tries to find an entry which has
- no _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs parameter. If no such entry is found,
- then dhcpd acts as if there is no entry in the dhcpd.conf
- file for that client, even if there is an entry for that
+ When dhcpd tries to find a _\bh_\bo_\bs_\bt declaration for a client,
+ it first looks for a _\bh_\bo_\bs_\bt declaration which has a _\bf_\bi_\bx_\be_\bd_\b-
+ _\ba_\bd_\bd_\br_\be_\bs_\bs parameter which matches the subnet or shared net-
+ work on which the client is booting. If it doesn't find
+ any such entry, it then tries to find an entry which has
+ no _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs parameter. If no such entry is found,
+ then dhcpd acts as if there is no entry in the dhcpd.conf
+ file for that client, even if there is an entry for that
client on a different subnet or shared network.
E\bEX\bXA\bAM\bMP\bPL\bLE\bES\bS
subnet 204.254.239.0 netmask 255.255.255.224 {
_\bs_\bu_\bb_\bn_\be_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs_\b._\b._\b.
range 204.254.239.10 204.254.239.30;
- }
dhcpd.conf(5) dhcpd.conf(5)
+ }
subnet 204.254.239.32 netmask 255.255.255.224 {
_\bs_\bu_\bb_\bn_\be_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs_\b._\b._\b.
range 204.254.239.42 204.254.239.62;
Figure 1
- Notice that after the server-identifier declaration,
- there's a place for global parameters. These might be
- things like the organization's domain name, the addresses
- of the name servers (if they are common to the entire
+ Notice that after the server-identifier declaration,
+ there's a place for global parameters. These might be
+ things like the organization's domain name, the addresses
+ of the name servers (if they are common to the entire
organization), and so on. So, for example:
option domain-name "isc.org";
Figure 2
- As you can see in Figure 2, it's legal to specify host
- addresses in parameters as domain names rather than as
- numeric IP addresses. If a given hostname resolves to
- more than one IP address (for example, if that host has
- two ethernet interfaces), both addresses are supplied to
+ As you can see in Figure 2, it's legal to specify host
+ addresses in parameters as domain names rather than as
+ numeric IP addresses. If a given hostname resolves to
+ more than one IP address (for example, if that host has
+ two ethernet interfaces), both addresses are supplied to
the client.
- In Figure 1, you can see that both the shared-network
- statement and the subnet statements can have parameters.
- Let us say that the shared network _\bI_\bS_\bC_\b-_\bB_\bI_\bG_\bG_\bI_\bE supports an
- entire department - perhaps the accounting department.
- If accounting has its own domain, then a shared-network-
+ In Figure 1, you can see that both the shared-network
+ statement and the subnet statements can have parameters.
+ Let us say that the shared network _\bI_\bS_\bC_\b-_\bB_\bI_\bG_\bG_\bI_\bE supports an
+ entire department - perhaps the accounting department.
+ If accounting has its own domain, then a shared-network-
specific parameter might be:
option domain-name "accounting.isc.org";
-
3
dhcpd.conf(5) dhcpd.conf(5)
- All subnet declarations appearing in the shared-network
- declaration would then have the domain-name option set to
+ All subnet declarations appearing in the shared-network
+ declaration would then have the domain-name option set to
"accounting.isc.org" instead of just "isc.org".
The most obvious reason for having subnet-specific parame-
- ters as shown in Figure 1 is that each subnet, of neces-
- sity, has its own router. So for the first subnet, for
+ ters as shown in Figure 1 is that each subnet, of neces-
+ sity, has its own router. So for the first subnet, for
example, there should be something like:
option routers 204.254.239.1;
- Note that the address here is specified numerically.
+ Note that the address here is specified numerically.
This is not required - if you have a different domain name
- for each interface on your router, it's perfectly legiti-
- mate to use the domain name for that interface instead of
+ for each interface on your router, it's perfectly legiti-
+ mate to use the domain name for that interface instead of
the numeric address. However, in many cases there may be
- only one domain name for all of a router's IP addresses,
+ only one domain name for all of a router's IP addresses,
and it would not be appropriate to use that name here.
- In Figure 1 there is also a _\bg_\br_\bo_\bu_\bp statement, which pro-
- vides common parameters for a set of three hosts - zappo,
- beppo and harpo. As you can see, these hosts are all in
- the test.isc.org domain, so it might make sense for a
- group-specific parameter to override the domain name sup-
+ In Figure 1 there is also a _\bg_\br_\bo_\bu_\bp statement, which pro-
+ vides common parameters for a set of three hosts - zappo,
+ beppo and harpo. As you can see, these hosts are all in
+ the test.isc.org domain, so it might make sense for a
+ group-specific parameter to override the domain name sup-
plied to these hosts:
option domain-name "test.isc.org";
Also, given the domain they're in, these are probably test
- machines. If we wanted to test the DHCP leasing mecha-
+ machines. If we wanted to test the DHCP leasing mecha-
nism, we might set the lease timeout somewhat shorter than
the default:
default-lease-time 120;
You may have noticed that while some parameters start with
- the _\bo_\bp_\bt_\bi_\bo_\bn keyword, some do not. Parameters starting
+ the _\bo_\bp_\bt_\bi_\bo_\bn keyword, some do not. Parameters starting
with the _\bo_\bp_\bt_\bi_\bo_\bn keyword correspond to actual DHCP options,
while parameters that do not start with the option keyword
either control the behaviour of the DHCP server (e.g., how
- long a lease dhcpd will give out), or specify client
+ long a lease dhcpd will give out), or specify client
parameters that are not optional in the DHCP protocol (for
example, server-name and filename).
- In Figure 1, each host had _\bh_\bo_\bs_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs.
- These could include such things as the _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option,
- the name of a file to upload (the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\b) _\ba_\bn_\bd
- _\bt_\bh_\be _\ba_\bd_\bd_\br_\be_\bs_\bs _\bo_\bf _\bt_\bh_\be _\bs_\be_\br_\bv_\be_\br _\bf_\br_\bo_\bm _\bw_\bh_\bi_\bc_\bh _\bt_\bo _\bu_\bp_\bl_\bo_\ba_\bd _\bt_\bh_\be _\bf_\bi_\bl_\be
- _\b(_\bt_\bh_\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter). In general, any parameter
- can appear anywhere that parameters are allowed, and will
- be applied according to the scope in which the parameter
+ In Figure 1, each host had _\bh_\bo_\bs_\bt_\b-_\bs_\bp_\be_\bc_\bi_\bf_\bi_\bc _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs.
+ These could include such things as the _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option,
+ the name of a file to upload (the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\b) _\ba_\bn_\bd
+ _\bt_\bh_\be _\ba_\bd_\bd_\br_\be_\bs_\bs _\bo_\bf _\bt_\bh_\be _\bs_\be_\br_\bv_\be_\br _\bf_\br_\bo_\bm _\bw_\bh_\bi_\bc_\bh _\bt_\bo _\bu_\bp_\bl_\bo_\ba_\bd _\bt_\bh_\be _\bf_\bi_\bl_\be
+ _\b(_\bt_\bh_\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter). In general, any parameter
+ can appear anywhere that parameters are allowed, and will
+ be applied according to the scope in which the parameter
appears.
dhcpd.conf(5) dhcpd.conf(5)
- Imagine that you have a site with a lot of NCD X-
- Terminals. These terminals come in a variety of models,
- and you want to specify the boot files for each models.
- One way to do this would be to have host declarations for
+ Imagine that you have a site with a lot of NCD X-
+ Terminals. These terminals come in a variety of models,
+ and you want to specify the boot files for each models.
+ One way to do this would be to have host declarations for
each server and group them by model:
group {
s\bse\ber\brv\bve\ber\br-\b-i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be;\b;
- The server-identifier declaration must be used exactly
+ The server-identifier declaration must be used exactly
once in each dhcpd.conf file to tell dhcpd what IP address
- to use as its server identifier, as required by the DHCP
- protocol. On a machine with a single interface, the
- server identifier should be the primary address of that
- interface. On machines with multiple interfaces, the
- address of one such interface must be chosen. Any
+ to use as its server identifier, as required by the DHCP
+ protocol. On a machine with a single interface, the
+ server identifier should be the primary address of that
+ interface. On machines with multiple interfaces, the
+ address of one such interface must be chosen. Any
address may be chosen, as long as it is the address of one
of the interfaces of that machine.
dhcpd.conf(5) dhcpd.conf(5)
- The _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement is used to inform the DHCP
+ The _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement is used to inform the DHCP
server that some IP subnets actually share the same physi-
- cal network. Any subnets in a shared network should be
- declared within a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement. Parameters
- specified in the _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement will be used
- when booting clients on those subnets unless parameters
- provided at the subnet or host level override them. If
+ cal network. Any subnets in a shared network should be
+ declared within a _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement. Parameters
+ specified in the _\bs_\bh_\ba_\br_\be_\bd_\b-_\bn_\be_\bt_\bw_\bo_\br_\bk statement will be used
+ when booting clients on those subnets unless parameters
+ provided at the subnet or host level override them. If
any subnet in a shared network has addresses available for
- dynamic allocation, those addresses are collected into a
- common pool for that shared network and assigned to
- clients as needed. There is no way to distinguish on
+ dynamic allocation, those addresses are collected into a
+ common pool for that shared network and assigned to
+ clients as needed. There is no way to distinguish on
which subnet of a shared network a client should boot.
_\bN_\ba_\bm_\be should be the name of the shared network. This name
- is used when printing debugging messages, so it should be
- descriptive for the shared network. The name may have
- the syntax of a valid domain name (although it will never
- be used as such), or it may be any arbitrary name,
+ is used when printing debugging messages, so it should be
+ descriptive for the shared network. The name may have
+ the syntax of a valid domain name (although it will never
+ be used as such), or it may be any arbitrary name,
enclosed in quotes.
T\bTh\bhe\be _\bs_\bu_\bb_\bn_\be_\bt s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
[ _\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn_\bs ]
}\b}
- The _\bs_\bu_\bb_\bn_\be_\bt statement is used to provide dhcpd with enough
- information to tell whether or not an IP address is on
- that subnet. It may also be used to provide subnet-
- specific parameters and to specify what addresses may be
- dynamically allocated to clients booting on that subnet.
- Such addresses are specified using the _\br_\ba_\bn_\bg_\be declaration.
+ The _\bs_\bu_\bb_\bn_\be_\bt statement is used to provide dhcpd with enough
+ information to tell whether or not an IP address is on
+ that subnet. It may also be used to provide subnet-
+ specific parameters and to specify what addresses may be
+ dynamically allocated to clients booting on that subnet.
+ Such addresses are specified using the _\br_\ba_\bn_\bg_\be declaration.
- The _\bs_\bu_\bb_\bn_\be_\bt_\b-_\bn_\bu_\bm_\bb_\be_\br should be an IP address or domain name
- which resolves to the subnet number of the subnet being
+ The _\bs_\bu_\bb_\bn_\be_\bt_\b-_\bn_\bu_\bm_\bb_\be_\br should be an IP address or domain name
+ which resolves to the subnet number of the subnet being
described. The _\bn_\be_\bt_\bm_\ba_\bs_\bk should be an IP address or domain
name which resolves to the subnet mask of the subnet being
described. The subnet number, together with the netmask,
- are sufficient to determine whether any given IP address
+ are sufficient to determine whether any given IP address
is on the specified subnet.
+ Although a netmask must be given with every subnet decla-
+ ration, it is recommended that if there is any variance in
+ subnet masks at a site, a subnet-mask option statement be
+ used in each subnet declaration to set the desired subnet
+ mask, since any subnet-mask option statement will override
+ the subnet mask declared in the subnet statement.
+
T\bTh\bhe\be _\br_\ba_\bn_\bg_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
r\bra\ban\bng\bge\be [ d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp ] _\bl_\bo_\bw_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [ _\bh_\bi_\bg_\bh_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs];\b;
- For any subnet on which addresses will be assigned dynami-
- cally, there must be at least one _\br_\ba_\bn_\bg_\be statement. The
- range statement gives the lowest and highest IP addresses
- in a range. All IP addresses in the range should be in
- the subnet in which the _\br_\ba_\bn_\bg_\be statement is declared. The
- _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp flag may be specified if addresses in the
- specified range may be dynamically assigned to BOOTP
- clients as well as DHCP clients. When specifying a
+ For any subnet on which addresses will be assigned
dhcpd.conf(5) dhcpd.conf(5)
- single address, _\bh_\bi_\bg_\bh_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs can be omitted.
+ dynamically, there must be at least one _\br_\ba_\bn_\bg_\be statement.
+ The range statement gives the lowest and highest IP
+ addresses in a range. All IP addresses in the range
+ should be in the subnet in which the _\br_\ba_\bn_\bg_\be statement is
+ declared. The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp flag may be specified if
+ addresses in the specified range may be dynamically
+ assigned to BOOTP clients as well as DHCP clients. When
+ specifying a single address, _\bh_\bi_\bg_\bh_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs can be omitted.
T\bTh\bhe\be _\bh_\bo_\bs_\bt s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
[ _\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn_\bs ]
}\b}
- There must be at least one h\bho\bos\bst\bt statement for every BOOTP
- client that is to be served. h\bho\bos\bst\bt statements may also be
- specified for DHCP clients, although this is not required
+ There must be at least one h\bho\bos\bst\bt statement for every BOOTP
+ client that is to be served. h\bho\bos\bst\bt statements may also be
+ specified for DHCP clients, although this is not required
unless booting is only enabled for known hosts.
- If it is desirable to be able to boot a DHCP or BOOTP
- client on more than one subnet with fixed addresses, more
- than one address may be specified in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
- parameter, or more than one h\bho\bos\bst\bt statement may be speci-
+ If it is desirable to be able to boot a DHCP or BOOTP
+ client on more than one subnet with fixed addresses, more
+ than one address may be specified in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ parameter, or more than one h\bho\bos\bst\bt statement may be speci-
fied.
- If client-specific boot parameters must change based on
+ If client-specific boot parameters must change based on
the network to which the client is attached, then multiple
h\bho\bos\bst\bt statements should be used.
- If a client is to be booted using a fixed address if it's
+ If a client is to be booted using a fixed address if it's
possible, but should be allocated a dynamic address other-
- wise, then a h\bho\bos\bst\bt statement must be specified without a
+ wise, then a h\bho\bos\bst\bt statement must be specified without a
f\bfi\bix\bxe\bed\bd-\b-a\bad\bdd\bdr\bre\bes\bss\bs clause. _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be should be a name identify-
- ing the host. If a _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option is not specified for
+ ing the host. If a _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option is not specified for
the host, _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be is used.
- _\bH_\bo_\bs_\bt declarations are matched to actual DHCP or BOOTP
+ _\bH_\bo_\bs_\bt declarations are matched to actual DHCP or BOOTP
clients by matching the dhcp-client-identifier option
- specified in the _\bh_\bo_\bs_\bt declaration to the one supplied by
+ specified in the _\bh_\bo_\bs_\bt declaration to the one supplied by
the client, or, if the _\bh_\bo_\bs_\bt declaration or the client does
- not provide a dhcp-client-identifier option, by matching
+ not provide a dhcp-client-identifier option, by matching
the _\bh_\ba_\br_\bd_\bw_\ba_\br_\be parameter in the _\bh_\bo_\bs_\bt declaration to the net-
- work hardware address supplied by the client. BOOTP
- clients do not normally provide a _\bd_\bh_\bc_\bp_\b-_\bc_\bl_\bi_\be_\bn_\bt_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br,
- so the hardware address must be used for all clients that
+ work hardware address supplied by the client. BOOTP
+ clients do not normally provide a _\bd_\bh_\bc_\bp_\b-_\bc_\bl_\bi_\be_\bn_\bt_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br,
+ so the hardware address must be used for all clients that
may boot using the BOOTP protocol.
T\bTh\bhe\be _\bg_\br_\bo_\bu_\bp s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
g\bgr\bro\bou\bup\bp {
[ _\bp_\ba_\br_\ba_\bm_\be_\bt_\be_\br_\bs ]
[ _\bd_\be_\bc_\bl_\ba_\br_\ba_\bt_\bi_\bo_\bn_\bs ]
- }\b}
-
- The group statement is used simply to apply one or more
- parameters to a group of declarations. It can be used to
- group hosts, shared networks, subnets, or even other
- groups.
-
dhcpd.conf(5) dhcpd.conf(5)
+ }\b}
+
+ The group statement is used simply to apply one or more
+ parameters to a group of declarations. It can be used to
+ group hosts, shared networks, subnets, or even other
+ groups.
+
R\bRE\bEF\bFE\bER\bRE\bEN\bNC\bCE\bE:\b: P\bPA\bAR\bRA\bAM\bME\bET\bTE\bER\bRS\bS
T\bTh\bhe\be _\bd_\be_\bf_\ba_\bu_\bl_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bt_\bi_\bm_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
m\bma\bax\bx-\b-l\ble\bea\bas\bse\be-\b-t\bti\bim\bme\be _\bt_\bi_\bm_\be;\b;
- _\bT_\bi_\bm_\be should be the maximum length in seconds that will be
- assigned to a lease if the client requesting the lease
+ _\bT_\bi_\bm_\be should be the maximum length in seconds that will be
+ assigned to a lease if the client requesting the lease
asks for a specific expiration time.
T\bTh\bhe\be _\bh_\ba_\br_\bd_\bw_\ba_\br_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
h\bha\bar\brd\bdw\bwa\bar\bre\be _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\bt_\by_\bp_\be _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- In order for a BOOTP client to be recognized, its network
- hardware address must be declared using a _\bh_\ba_\br_\bd_\bw_\ba_\br_\be clause
- in the _\bh_\bo_\bs_\bt statement. _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\bt_\by_\bp_\be must be the name of
- a physical hardware interface type. Currently, only the
- e\bet\bth\bhe\ber\brn\bne\bet\bt type is recognized, although support for t\bto\bok\bke\ben\bn-\b-
+ In order for a BOOTP client to be recognized, its network
+ hardware address must be declared using a _\bh_\ba_\br_\bd_\bw_\ba_\br_\be clause
+ in the _\bh_\bo_\bs_\bt statement. _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\bt_\by_\bp_\be must be the name of
+ a physical hardware interface type. Currently, only the
+ e\bet\bth\bhe\ber\brn\bne\bet\bt type is recognized, although support for t\bto\bok\bke\ben\bn-\b-
r\bri\bin\bng\bg and f\bfd\bdd\bdi\bi hardware types would also be desirable. The
- _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs should be a set of hexadecimal octets
- (numbers from 0 through ff) seperated by colons. The
+ _\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs should be a set of hexadecimal octets
+ (numbers from 0 through ff) seperated by colons. The
_\bh_\ba_\br_\bd_\bw_\ba_\br_\be_\bf_\bR _\bs_\bt_\ba_\bt_\be_\bm_\be_\bn_\bt _\bm_\ba_\by _\ba_\bl_\bs_\bo _\bb_\be _\bu_\bs_\be_\bd _\bf_\bo_\br _\bD_\bH_\bC_\bP _\bc_\bl_\bi_\be_\bn_\bt_\bs_\b.
T\bTh\bhe\be _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
f\bfi\bil\ble\ben\bna\bam\bme\be "\b"_\bf_\bi_\bl_\be_\bn_\ba_\bm_\be"\b";\b;
- The _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement can be used to specify the name of
- the initial boot file which is to be loaded by a client.
+ The _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement can be used to specify the name of
+ the initial boot file which is to be loaded by a client.
The _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be should be a filename recognizable to whatever
- file transfer protocol the client can be expected to use
+ file transfer protocol the client can be expected to use
to load the file.
T\bTh\bhe\be _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
The _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be statement can be used to inform the client
of the name of the server from which it is booting. _\bN_\ba_\bm_\be
- should be the name that will be provided to the client.
- T\bTh\bhe\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
- n\bne\bex\bxt\bt-\b-s\bse\ber\brv\bve\ber\br _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be;\b;
- The _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br statement is used to specify the host
+ 8
- 8
+dhcpd.conf(5) dhcpd.conf(5)
+ should be the name that will be provided to the client.
-dhcpd.conf(5) dhcpd.conf(5)
+ T\bTh\bhe\be _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
+ n\bne\bex\bxt\bt-\b-s\bse\ber\brv\bve\ber\br _\bs_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be;\b;
- address of the server from which the initial boot file
- (specified in the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement) is to be loaded.
- _\bS_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be should be a numeric IP address or a domain
- name. If no _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter applies to a given
- client, the address specified in the _\bs_\be_\br_\bv_\be_\br_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br
+ The _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br statement is used to specify the host
+ address of the server from which the initial boot file
+ (specified in the _\bf_\bi_\bl_\be_\bn_\ba_\bm_\be statement) is to be loaded.
+ _\bS_\be_\br_\bv_\be_\br_\b-_\bn_\ba_\bm_\be should be a numeric IP address or a domain
+ name. If no _\bn_\be_\bx_\bt_\b-_\bs_\be_\br_\bv_\be_\br parameter applies to a given
+ client, the address specified in the _\bs_\be_\br_\bv_\be_\br_\b-_\bi_\bd_\be_\bn_\bt_\bi_\bf_\bi_\be_\br
statement is used.
T\bTh\bhe\be _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
f\bfi\bix\bxe\bed\bd-\b-a\bad\bdd\bdr\bre\bes\bss\bs _\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs statement is used to assign one or more
- fixed IP addresses to a client. It should only appear in
+ The _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs statement is used to assign one or more
+ fixed IP addresses to a client. It should only appear in
a _\bh_\bo_\bs_\bt declaration. If more than one address is supplied,
- then when the client boots, it will be assigned the
- address which corresponds to the network on which it is
- booting. If none of the addresses in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
- statement are on the network on which the client is boot-
- ing, that client will not match the _\bh_\bo_\bs_\bt declaration con-
+ then when the client boots, it will be assigned the
+ address which corresponds to the network on which it is
+ booting. If none of the addresses in the _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ statement are on the network on which the client is boot-
+ ing, that client will not match the _\bh_\bo_\bs_\bt declaration con-
taining that _\bf_\bi_\bx_\be_\bd_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs statement. Each _\ba_\bd_\bd_\br_\be_\bs_\bs should
be either an IP address or a domain name which resolves to
one or more IP addresses.
d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp-\b-l\ble\bea\bas\bse\be-\b-c\bcu\but\bto\bof\bff\bf _\bd_\ba_\bt_\be;\b;
- The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bc_\bu_\bt_\bo_\bf_\bf statement sets the ending
+ The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bc_\bu_\bt_\bo_\bf_\bf statement sets the ending
time for all leases assigned dynamically to BOOTP clients.
- Because BOOTP clients do not have any way of renewing
- leases, and don't know that their leases could expire, by
+ Because BOOTP clients do not have any way of renewing
+ leases, and don't know that their leases could expire, by
default dhcpd assignes infinite leases to all BOOTP
clients. However, it may make sense in some situations to
- set a cutoff date for all BOOTP leases - for example, the
+ set a cutoff date for all BOOTP leases - for example, the
end of a school term, or the time at night when a facility
is closed and all machines are required to be powered off.
W YYYY/MM/DD HH:MM:SS
- W is the day of the week expressed as a number from zero
- (Sunday) to six (Saturday). YYYY is the year, including
+ W is the day of the week expressed as a number from zero
+ (Sunday) to six (Saturday). YYYY is the year, including
the century. MM is the month expressed as a number from 1
- to 12. DD is the day of the month, counting from 1. HH
- is the hour, from zero to 23. MM is the minute and SS is
- the second. The time is always in Greenwich Mean Time
- (GMT), not local time.
+ to 12. DD is the day of the month, counting from 1. HH
+ is the hour, from zero to 23. MM is the minute and SS is
- T\bTh\bhe\be _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
- d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp-\b-l\ble\bea\bas\bse\be-\b-l\ble\ben\bng\bgt\bth\bh _\bl_\be_\bn_\bg_\bt_\bh;\b;
+ 9
- 9
+dhcpd.conf(5) dhcpd.conf(5)
+ the second. The time is always in Greenwich Mean Time
+ (GMT), not local time.
-dhcpd.conf(5) dhcpd.conf(5)
+ T\bTh\bhe\be _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
+ d\bdy\byn\bna\bam\bmi\bic\bc-\b-b\bbo\boo\bot\btp\bp-\b-l\ble\bea\bas\bse\be-\b-l\ble\ben\bng\bgt\bth\bh _\bl_\be_\bn_\bg_\bt_\bh;\b;
- The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh statement is used to set
- the length of leases dynamically assigned to BOOTP
- clients. At some sites, it may be possible to assume
- that a lease is no longer in use if its holder has not
- used BOOTP or DHCP to get its address within a certain
+ The _\bd_\by_\bn_\ba_\bm_\bi_\bc_\b-_\bb_\bo_\bo_\bt_\bp_\b-_\bl_\be_\ba_\bs_\be_\b-_\bl_\be_\bn_\bg_\bt_\bh statement is used to set
+ the length of leases dynamically assigned to BOOTP
+ clients. At some sites, it may be possible to assume
+ that a lease is no longer in use if its holder has not
+ used BOOTP or DHCP to get its address within a certain
time period. The period is specified in _\bl_\be_\bn_\bg_\bt_\bh as a num-
- ber of seconds. If a client reboots using BOOTP during
+ ber of seconds. If a client reboots using BOOTP during
the timeout period, the lease duration is reset to _\bl_\be_\bn_\bg_\bt_\bh,
- so a BOOTP client that boots frequently enough will never
+ so a BOOTP client that boots frequently enough will never
lose its lease. Needless to say, this parameter should be
adjusted with extreme caution.
b\bbo\boo\bot\bt-\b-u\bun\bnk\bkn\bno\bow\bwn\bn-\b-c\bcl\bli\bie\ben\bnt\bts\bs _\bf_\bl_\ba_\bg;\b;
- The _\bb_\bo_\bo_\bt_\b-_\bu_\bn_\bk_\bn_\bo_\bw_\bn_\b-_\bc_\bl_\bi_\be_\bn_\bt_\bs statement is used to tell dhcpd
- whether or not to dynamically assign addresses to unknown
+ The _\bb_\bo_\bo_\bt_\b-_\bu_\bn_\bk_\bn_\bo_\bw_\bn_\b-_\bc_\bl_\bi_\be_\bn_\bt_\bs statement is used to tell dhcpd
+ whether or not to dynamically assign addresses to unknown
DHCP clients. If _\bf_\bl_\ba_\bg is true (the default), then
addresses are dynamically assigned to unknown DHCP clients
when available. If _\bf_\bl_\ba_\bg is false, then addresses are pro-
- vided only to DHCP clients which match at least one host
+ vided only to DHCP clients which match at least one host
declaration.
T\bTh\bhe\be _\bg_\be_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be_\bs s\bst\bta\bat\bte\bem\bme\ben\bnt\bt
g\bge\bet\bt-\b-l\ble\bea\bas\bse\be-\b-h\bho\bos\bst\btn\bna\bam\bme\bes\bs _\bf_\bl_\ba_\bg;\b;
- The _\bg_\be_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be_\bs statement is used to tell dhcpd
+ The _\bg_\be_\bt_\b-_\bl_\be_\ba_\bs_\be_\b-_\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be_\bs statement is used to tell dhcpd
whether or not to look up the domain name corresponding to
- the IP address of each address in the lease pool and use
- that address for the DHCP _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option. If _\bf_\bl_\ba_\bg is
- true, then this lookup is done for all addresses in the
- current scope. By default, or if _\bf_\bl_\ba_\bg is false, no
+ the IP address of each address in the lease pool and use
+ that address for the DHCP _\bh_\bo_\bs_\bt_\bn_\ba_\bm_\be option. If _\bf_\bl_\ba_\bg is
+ true, then this lookup is done for all addresses in the
+ current scope. By default, or if _\bf_\bl_\ba_\bg is false, no
lookups are done.
R\bRE\bEF\bFE\bER\bRE\bEN\bNC\bCE\bE:\b: O\bOP\bPT\bTI\bIO\bON\bN S\bST\bTA\bAT\bTE\bEM\bME\bEN\bNT\bTS\bS
- DHCP _\bo_\bp_\bt_\bi_\bo_\bn statements always start with the _\bo_\bp_\bt_\bi_\bo_\bn key-
+ DHCP _\bo_\bp_\bt_\bi_\bo_\bn statements always start with the _\bo_\bp_\bt_\bi_\bo_\bn key-
word, followed by an option name, followed by option data.
- The option names and data formats are described below.
- It is not necessary to exhaustively specify all DHCP
- options - only those options which are needed by clients
+ The option names and data formats are described below.
+ It is not necessary to exhaustively specify all DHCP
+ options - only those options which are needed by clients
must be specified.
- Option data comes in a variety of formats, as defined
+ Option data comes in a variety of formats, as defined
below:
- The i\bip\bp-\b-a\bad\bdd\bdr\bre\bes\bss\bs data type can be entered either as an
- explicit IP address (e.g., 239.254.197.10) or as a domain
- name (e.g., haagen.isc.org). When entering a domain name,
- be sure that that domain name resolves to a single IP
- address.
-
- The i\bin\bnt\bt3\b32\b2 data type specifies a signed 32-bit integer.
dhcpd.conf(5) dhcpd.conf(5)
+ The i\bip\bp-\b-a\bad\bdd\bdr\bre\bes\bss\bs data type can be entered either as an
+ explicit IP address (e.g., 239.254.197.10) or as a domain
+ name (e.g., haagen.isc.org). When entering a domain name,
+ be sure that that domain name resolves to a single IP
+ address.
+
+ The i\bin\bnt\bt3\b32\b2 data type specifies a signed 32-bit integer.
The u\bui\bin\bnt\bt3\b32\b2 data type specifies an unsigned 32-bit integer.
The i\bin\bnt\bt1\b16\b6 and u\bui\bin\bnt\bt1\b16\b6 data types specify signed and
- unsigned 16-bit integers. The i\bin\bnt\bt8\b8 and u\bui\bin\bnt\bt8\b8 data types
- specify signed and unsigned 8-bit integers. Unsigned
+ unsigned 16-bit integers. The i\bin\bnt\bt8\b8 and u\bui\bin\bnt\bt8\b8 data types
+ specify signed and unsigned 8-bit integers. Unsigned
8-bit integers are also sometimes referred to as octets.
- The s\bst\btr\bri\bin\bng\bg data type specifies an NVT ASCII string, which
- must be enclosed in double quotes - for example, to spec-
+ The s\bst\btr\bri\bin\bng\bg data type specifies an NVT ASCII string, which
+ must be enclosed in double quotes - for example, to spec-
ify a domain-name option, the syntax would be
option domain-name "isc.org";
- The f\bfl\bla\bag\bg data type specifies a boolean value. Booleans
- can be either true or false (or on or off, if that makes
+ The f\bfl\bla\bag\bg data type specifies a boolean value. Booleans
+ can be either true or false (or on or off, if that makes
more sense to you).
- The d\bda\bat\bta\ba-\b-s\bst\btr\bri\bin\bng\bg data type specifies either an NVT ASCII
- string enclosed in double quotes, or a series of octets
+ The d\bda\bat\bta\ba-\b-s\bst\btr\bri\bin\bng\bg data type specifies either an NVT ASCII
+ string enclosed in double quotes, or a series of octets
specified in hexadecimal, seperated by colons. For exam-
ple:
or
option client-identifier 43:4c:49:45:54:2d:46:4f:4f;
- The documentation for the various options mentioned below
- is taken from the latest IETF draft document on DHCP
- options. Options which are not listed by name may be
- defined by the name option-_\bn_\bn_\bn, where _\bn_\bn_\bn _\bi_\bs _\bt_\bh_\be _\bd_\be_\bc_\bi_\bm_\ba_\bl
+ The documentation for the various options mentioned below
+ is taken from the latest IETF draft document on DHCP
+ options. Options which are not listed by name may be
+ defined by the name option-_\bn_\bn_\bn, where _\bn_\bn_\bn _\bi_\bs _\bt_\bh_\be _\bd_\be_\bc_\bi_\bm_\ba_\bl
_\bn_\bu_\bm_\bb_\be_\br _\bo_\bf _\bt_\bh_\be _\bo_\bp_\bt_\bi_\bo_\bn _\bc_\bo_\bd_\be_\b. _\bT_\bh_\be_\bs_\be _\bo_\bp_\bt_\bi_\bo_\bn_\bs _\bm_\ba_\by _\bb_\be _\bf_\bo_\bl_\bl_\bo_\bw_\be_\bd
- _\be_\bi_\bt_\bh_\be_\br _\bb_\by _\ba _\bs_\bt_\br_\bi_\bn_\bg_\b, _\be_\bn_\bc_\bl_\bo_\bs_\be_\bd _\bi_\bn _\bq_\bu_\bo_\bt_\be_\bs_\b, _\bo_\br _\bb_\by _\ba _\bs_\be_\br_\bi_\be_\bs _\bo_\bf
- _\bo_\bc_\bt_\be_\bt_\bs_\b, _\be_\bx_\bp_\br_\be_\bs_\bs_\be_\bd _\ba_\bs _\bt_\bw_\bo_\b-_\bd_\bi_\bg_\bi_\bt _\bh_\be_\bx_\ba_\bd_\be_\bc_\bi_\bm_\ba_\bl _\bn_\bu_\bm_\bb_\be_\br_\bs _\bs_\be_\bp_\be_\br_\b-
+ _\be_\bi_\bt_\bh_\be_\br _\bb_\by _\ba _\bs_\bt_\br_\bi_\bn_\bg_\b, _\be_\bn_\bc_\bl_\bo_\bs_\be_\bd _\bi_\bn _\bq_\bu_\bo_\bt_\be_\bs_\b, _\bo_\br _\bb_\by _\ba _\bs_\be_\br_\bi_\be_\bs _\bo_\bf
+ _\bo_\bc_\bt_\be_\bt_\bs_\b, _\be_\bx_\bp_\br_\be_\bs_\bs_\be_\bd _\ba_\bs _\bt_\bw_\bo_\b-_\bd_\bi_\bg_\bi_\bt _\bh_\be_\bx_\ba_\bd_\be_\bc_\bi_\bm_\ba_\bl _\bn_\bu_\bm_\bb_\be_\br_\bs _\bs_\be_\bp_\be_\br_\b-
_\ba_\bt_\be_\bd _\bb_\by _\bc_\bo_\bl_\bo_\bn_\bs_\b. _\bF_\bo_\br _\be_\bx_\ba_\bm_\bp_\bl_\be_\b:
option option-133 "my-option-133-text";
option option-129 1:54:c9:2b:47;
- Because dhcpd does not know the format of these undefined
- option codes, no checking is done to ensure the correct-
+ Because dhcpd does not know the format of these undefined
+ option codes, no checking is done to ensure the correct-
ness of the entered data.
The standard options are:
o\bop\bpt\bti\bio\bon\bn s\bsu\bub\bbn\bne\bet\bt-\b-m\bma\bas\bsk\bk _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- The subnet mask option specifies the client's subnet mask
- as per RFC 950.
+ The subnet mask option specifies the client's subnet mask
+ as per RFC 950. If no subnet mask option is provided
- o\bop\bpt\bti\bio\bon\bn t\bti\bim\bme\be-\b-o\bof\bff\bfs\bse\bet\bt _\bi_\bn_\bt_\b3_\b2;\b;
- The time-offset option specifies the offset of the
- client's subnet in seconds from Coordinated Universal Time
- (UTC).
+ 11
- 11
+dhcpd.conf(5) dhcpd.conf(5)
+ anywhere in scope, as a last resort dhcpd will use the
+ subnet mask from the subnet declaration for the network on
+ which an address is being assigned. However, _\ba_\bn_\by subnet-
+ mask option declaration that is in scope for the address
+ being assigned will override the subnet mask specified in
+ the subnet declaration.
-dhcpd.conf(5) dhcpd.conf(5)
+ o\bop\bpt\bti\bio\bon\bn t\bti\bim\bme\be-\b-o\bof\bff\bfs\bse\bet\bt _\bi_\bn_\bt_\b3_\b2;\b;
+ The time-offset option specifies the offset of the
+ client's subnet in seconds from Coordinated Universal Time
+ (UTC).
o\bop\bpt\bti\bio\bon\bn r\bro\bou\but\bte\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The routers option specifies a list of IP addresses for
- routers on the client's subnet. Routers should be listed
+ The routers option specifies a list of IP addresses for
+ routers on the client's subnet. Routers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn t\bti\bim\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\b[_\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The time-server option specifies a list of RFC 868 time
+ The time-server option specifies a list of RFC 868 time
servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];
- The name-servers option specifies a list of IEN 116 name
+ The name-servers option specifies a list of IEN 116 name
servers available to the client. Servers should be listed
in order of preference.
- o\bop\bpt\bti\bio\bon\bn d\bdo\bom\bma\bai\bin\bn-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
+ o\bop\bpt\bti\bio\bon\bn d\bdo\bom\bma\bai\bin\bn-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
];\b;
- The domain-name-servers option specifies a list of Domain
- Name System (STD 13, RFC 1035) name servers available to
- the client. Servers should be listed in order of prefer-
+ The domain-name-servers option specifies a list of Domain
+ Name System (STD 13, RFC 1035) name servers available to
+ the client. Servers should be listed in order of prefer-
ence.
o\bop\bpt\bti\bio\bon\bn l\blo\bog\bg-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The log-server option specifies a list of MIT-LCS UDP log
+ The log-server option specifies a list of MIT-LCS UDP log
servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn c\bco\boo\bok\bki\bie\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The cookie server option specifies a list of RFC 865
+ The cookie server option specifies a list of RFC 865
cookie servers available to the client. Servers should be
listed in order of preference.
o\bop\bpt\bti\bio\bon\bn l\blp\bpr\br-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The LPR server option specifies a list of RFC 1179 line
- printer servers available to the client. Servers should
- be listed in order of preference.
+ The LPR server option specifies a list of RFC 1179 line
- o\bop\bpt\bti\bio\bon\bn i\bim\bmp\bpr\bre\bes\bss\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The impress-server option specifies a list of Imagen
- Impress servers available to the client. Servers should
- be listed in order of preference.
- o\bop\bpt\bti\bio\bon\bn r\bre\bes\bso\bou\bur\brc\bce\be-\b-l\blo\boc\bca\bat\bti\bio\bon\bn-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
- ... ];\b;
+ 12
- This option specifies a list of RFC 887 Resource Location
- 12
+dhcpd.conf(5) dhcpd.conf(5)
+ printer servers available to the client. Servers should
+ be listed in order of preference.
+ o\bop\bpt\bti\bio\bon\bn i\bim\bmp\bpr\bre\bes\bss\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
-dhcpd.conf(5) dhcpd.conf(5)
+ The impress-server option specifies a list of Imagen
+ Impress servers available to the client. Servers should
+ be listed in order of preference.
+ o\bop\bpt\bti\bio\bon\bn r\bre\bes\bso\bou\bur\brc\bce\be-\b-l\blo\boc\bca\bat\bti\bio\bon\bn-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ ... ];\b;
+ This option specifies a list of RFC 887 Resource Location
servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn h\bho\bos\bst\bt-\b-n\bna\bam\bme\be _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the name of the client. The name
+ This option specifies the name of the client. The name
may or may not be qualified with the local domain name (it
is preferable to use the domain-name option to specify the
- domain name). See RFC 1035 for character set restric-
+ domain name). See RFC 1035 for character set restric-
tions.
o\bop\bpt\bti\bio\bon\bn b\bbo\boo\bot\bt-\b-s\bsi\biz\bze\be _\bu_\bi_\bn_\bt_\b1_\b6;\b;
- This option specifies the length in 512-octet blocks of
+ This option specifies the length in 512-octet blocks of
the default boot image for the client.
o\bop\bpt\bti\bio\bon\bn m\bme\ber\bri\bit\bt-\b-d\bdu\bum\bmp\bp _\bs_\bt_\br_\bi_\bn_\bg;\b;
This option specifies the path-name of a file to which the
- client's core image should be dumped in the event the
- client crashes. The path is formatted as a character
+ client's core image should be dumped in the event the
+ client crashes. The path is formatted as a character
string consisting of characters from the NVT ASCII charac-
ter set.
o\bop\bpt\bti\bio\bon\bn d\bdo\bom\bma\bai\bin\bn-\b-n\bna\bam\bme\be _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the domain name that client should
+ This option specifies the domain name that client should
use when resolving hostnames via the Domain Name System.
o\bop\bpt\bti\bio\bon\bn s\bsw\bwa\bap\bp-\b-s\bse\ber\brv\bve\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
o\bop\bpt\bti\bio\bon\bn r\bro\boo\bot\bt-\b-p\bpa\bat\bth\bh _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the path-name that contains the
- client's root disk. The path is formatted as a character
+ This option specifies the path-name that contains the
+ client's root disk. The path is formatted as a character
string consisting of characters from the NVT ASCII charac-
ter set.
o\bop\bpt\bti\bio\bon\bn i\bip\bp-\b-f\bfo\bor\brw\bwa\bar\brd\bdi\bin\bng\bg _\bf_\bl_\ba_\bg;\b;
- This option specifies whether the client should configure
- its IP layer for packet forwarding. A value of 0 means
- disable IP forwarding, and a value of 1 means enable IP
- forwarding.
-
- o\bop\bpt\bti\bio\bon\bn n\bno\bon\bn-\b-l\blo\boc\bca\bal\bl-\b-s\bso\bou\bur\brc\bce\be-\b-r\bro\bou\but\bti\bin\bng\bg _\bf_\bl_\ba_\bg;\b;
-
- This option specifies whether the client should configure
- its IP layer to allow forwarding of datagrams with non-
- local source routes (see Section 3.3.5 of [4] for a dis-
- cussion of this topic). A value of 0 means disallow for-
- warding of such datagrams, and a value of 1 means allow
-
13
dhcpd.conf(5) dhcpd.conf(5)
+ This option specifies whether the client should configure
+ its IP layer for packet forwarding. A value of 0 means
+ disable IP forwarding, and a value of 1 means enable IP
forwarding.
- o\bop\bpt\bti\bio\bon\bn p\bpo\bol\bli\bic\bcy\by-\b-f\bfi\bil\blt\bte\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ o\bop\bpt\bti\bio\bon\bn n\bno\bon\bn-\b-l\blo\boc\bca\bal\bl-\b-s\bso\bou\bur\brc\bce\be-\b-r\bro\bou\but\bti\bin\bng\bg _\bf_\bl_\ba_\bg;\b;
+
+ This option specifies whether the client should configure
+ its IP layer to allow forwarding of datagrams with non-
+ local source routes (see Section 3.3.5 of [4] for a dis-
+ cussion of this topic). A value of 0 means disallow for-
+ warding of such datagrams, and a value of 1 means allow
+ forwarding.
+
+ o\bop\bpt\bti\bio\bon\bn p\bpo\bol\bli\bic\bcy\by-\b-f\bfi\bil\blt\bte\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
_\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies policy filters for non-local source
- routing. The filters consist of a list of IP addresses
- and masks which specify destination/mask pairs with which
+ This option specifies policy filters for non-local source
+ routing. The filters consist of a list of IP addresses
+ and masks which specify destination/mask pairs with which
to filter incoming source routes.
Any source routed datagram whose next-hop address does not
- match one of the filters should be discarded by the
+ match one of the filters should be discarded by the
client.
See STD 3 (RFC1122) for further information.
o\bop\bpt\bti\bio\bon\bn m\bma\bax\bx-\b-d\bdg\bgr\bra\bam\bm-\b-r\bre\bea\bas\bss\bse\bem\bmb\bbl\bly\by _\bu_\bi_\bn_\bt_\b1_\b6;\b;
- This option specifies the maximum size datagram that the
- client should be prepared to reassemble. The minimum
+ This option specifies the maximum size datagram that the
+ client should be prepared to reassemble. The minimum
value legal value is 576.
o\bop\bpt\bti\bio\bon\bn d\bde\bef\bfa\bau\bul\blt\bt-\b-i\bip\bp-\b-t\btt\btl\bl _\bu_\bi_\bn_\bt_\b8_\b;
- This option specifies the default time-to-live that the
+ This option specifies the default time-to-live that the
client should use on outgoing datagrams.
o\bop\bpt\bti\bio\bon\bn p\bpa\bat\bth\bh-\b-m\bmt\btu\bu-\b-a\bag\bgi\bin\bng\bg-\b-t\bti\bim\bme\beo\bou\but\bt _\bu_\bi_\bn_\bt_\b3_\b2;\b;
This option specifies the timeout (in seconds) to use when
- aging Path MTU values discovered by the mechanism defined
+ aging Path MTU values discovered by the mechanism defined
in RFC 1191.
o\bop\bpt\bti\bio\bon\bn p\bpa\bat\bth\bh-\b-m\bmt\btu\bu-\b-p\bpl\bla\bat\bte\bea\bau\bu-\b-t\bta\bab\bbl\ble\be _\bu_\bi_\bn_\bt_\b1_\b6 [,\b, _\bu_\bi_\bn_\bt_\b1_\b6 ... ];\b;
- This option specifies a table of MTU sizes to use when
+ This option specifies a table of MTU sizes to use when
performing Path MTU Discovery as defined in RFC 1191. The
- table is formatted as a list of 16-bit unsigned integers,
- ordered from smallest to largest. The minimum MTU value
+ table is formatted as a list of 16-bit unsigned integers,
+ ordered from smallest to largest. The minimum MTU value
cannot be smaller than 68.
o\bop\bpt\bti\bio\bon\bn i\bin\bnt\bte\ber\brf\bfa\bac\bce\be-\b-m\bmt\btu\bu _\bu_\bi_\bn_\bt_\b1_\b6;\b;
- This option specifies the MTU to use on this interface.
- The minimum legal value for the MTU is 68.
-
- o\bop\bpt\bti\bio\bon\bn a\bal\bll\bl-\b-s\bsu\bub\bbn\bne\bet\bts\bs-\b-l\blo\boc\bca\bal\bl _\bf_\bl_\ba_\bg;\b;
-
- This option specifies whether or not the client may assume
- that all subnets of the IP network to which the client is
- connected use the same MTU as the subnet of that network
- to which the client is directly connected. A value of 1
- indicates that all subnets share the same MTU. A value of
- 0 means that the client should assume that some subnets of
-
14
dhcpd.conf(5) dhcpd.conf(5)
+ This option specifies the MTU to use on this interface.
+ The minimum legal value for the MTU is 68.
+
+ o\bop\bpt\bti\bio\bon\bn a\bal\bll\bl-\b-s\bsu\bub\bbn\bne\bet\bts\bs-\b-l\blo\boc\bca\bal\bl _\bf_\bl_\ba_\bg;\b;
+
+ This option specifies whether or not the client may assume
+ that all subnets of the IP network to which the client is
+ connected use the same MTU as the subnet of that network
+ to which the client is directly connected. A value of 1
+ indicates that all subnets share the same MTU. A value of
+ 0 means that the client should assume that some subnets of
the directly connected network may have smaller MTUs.
o\bop\bpt\bti\bio\bon\bn b\bbr\bro\boa\bad\bdc\bca\bas\bst\bt-\b-a\bad\bdd\bdr\bre\bes\bss\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- This option specifies the broadcast address in use on the
+ This option specifies the broadcast address in use on the
client's subnet. Legal values for broadcast addresses are
specified in section 3.2.1.3 of STD 3 (RFC1122).
o\bop\bpt\bti\bio\bon\bn p\bpe\ber\brf\bfo\bor\brm\bm-\b-m\bma\bas\bsk\bk-\b-d\bdi\bis\bsc\bco\bov\bve\ber\bry\by _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
- perform subnet mask discovery using ICMP. A value of 0
- indicates that the client should not perform mask discov-
- ery. A value of 1 means that the client should perform
+ This option specifies whether or not the client should
+ perform subnet mask discovery using ICMP. A value of 0
+ indicates that the client should not perform mask discov-
+ ery. A value of 1 means that the client should perform
mask discovery.
o\bop\bpt\bti\bio\bon\bn m\bma\bas\bsk\bk-\b-s\bsu\bup\bpp\bpl\bli\bie\ber\br _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
- respond to subnet mask requests using ICMP. A value of 0
- indicates that the client should not respond. A value of
+ This option specifies whether or not the client should
+ respond to subnet mask requests using ICMP. A value of 0
+ indicates that the client should not respond. A value of
1 means that the client should respond.
o\bop\bpt\bti\bio\bon\bn r\bro\bou\but\bte\ber\br-\b-d\bdi\bis\bsc\bco\bov\bve\ber\bry\by _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
+ This option specifies whether or not the client should
solicit routers using the Router Discovery mechanism
- defined in RFC 1256. A value of 0 indicates that the
- client should not perform router discovery. A value of 1
+ defined in RFC 1256. A value of 0 indicates that the
+ client should not perform router discovery. A value of 1
means that the client should perform router discovery.
o\bop\bpt\bti\bio\bon\bn r\bro\bou\but\bte\ber\br-\b-s\bso\bol\bli\bic\bci\bit\bta\bat\bti\bio\bon\bn-\b-a\bad\bdd\bdr\bre\bes\bss\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs;\b;
- This option specifies the address to which the client
+ This option specifies the address to which the client
should transmit router solicitation requests.
- o\bop\bpt\bti\bio\bon\bn s\bst\bta\bat\bti\bic\bc-\b-r\bro\bou\but\bte\bes\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
+ o\bop\bpt\bti\bio\bon\bn s\bst\bta\bat\bti\bic\bc-\b-r\bro\bou\but\bte\bes\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs
_\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of static routes that the
- client should install in its routing cache. If multiple
- routes to the same destination are specified, they are
+ This option specifies a list of static routes that the
+ client should install in its routing cache. If multiple
+ routes to the same destination are specified, they are
listed in descending order of priority.
- The routes consist of a list of IP address pairs. The
- first address is the destination address, and the second
- address is the router for the destination.
-
- The default route (0.0.0.0) is an illegal destination for
- a static route. To specify the default route, use the
- r\bro\bou\but\bte\ber\brs\bs option.
- o\bop\bpt\bti\bio\bon\bn t\btr\bra\bai\bil\ble\ber\br-\b-e\ben\bnc\bca\bap\bps\bsu\bul\bla\bat\bti\bio\bon\bn _\bf_\bl_\ba_\bg;\b;
+ 15
- 15
+dhcpd.conf(5) dhcpd.conf(5)
+ The routes consist of a list of IP address pairs. The
+ first address is the destination address, and the second
+ address is the router for the destination.
-dhcpd.conf(5) dhcpd.conf(5)
+ The default route (0.0.0.0) is an illegal destination for
+ a static route. To specify the default route, use the
+ r\bro\bou\but\bte\ber\brs\bs option.
+ o\bop\bpt\bti\bio\bon\bn t\btr\bra\bai\bil\ble\ber\br-\b-e\ben\bnc\bca\bap\bps\bsu\bul\bla\bat\bti\bio\bon\bn _\bf_\bl_\ba_\bg;\b;
- This option specifies whether or not the client should
- negotiate the use of trailers (RFC 893 [14]) when using
- the ARP protocol. A value of 0 indicates that the client
- should not attempt to use trailers. A value of 1 means
+ This option specifies whether or not the client should
+ negotiate the use of trailers (RFC 893 [14]) when using
+ the ARP protocol. A value of 0 indicates that the client
+ should not attempt to use trailers. A value of 1 means
that the client should attempt to use trailers.
o\bop\bpt\bti\bio\bon\bn a\bar\brp\bp-\b-c\bca\bac\bch\bhe\be-\b-t\bti\bim\bme\beo\bou\but\bt _\bu_\bi_\bn_\bt_\b3_\b2;\b;
o\bop\bpt\bti\bio\bon\bn i\bie\bee\bee\be8\b80\b02\b2-\b-3\b3-\b-e\ben\bnc\bca\bap\bps\bsu\bul\bla\bat\bti\bio\bon\bn _\bf_\bl_\ba_\bg;\b;
This option specifies whether or not the client should use
- Ethernet Version 2 (RFC 894) or IEEE 802.3 (RFC 1042)
+ Ethernet Version 2 (RFC 894) or IEEE 802.3 (RFC 1042)
encapsulation if the interface is an Ethernet. A value of
- 0 indicates that the client should use RFC 894 encapsula-
- tion. A value of 1 means that the client should use RFC
+ 0 indicates that the client should use RFC 894 encapsula-
+ tion. A value of 1 means that the client should use RFC
1042 encapsulation.
o\bop\bpt\bti\bio\bon\bn d\bde\bef\bfa\bau\bul\blt\bt-\b-t\btc\bcp\bp-\b-t\btt\btl\bl _\bu_\bi_\bn_\bt_\b8;\b;
- This option specifies the default TTL that the client
- should use when sending TCP segments. The minimum value
+ This option specifies the default TTL that the client
+ should use when sending TCP segments. The minimum value
is 1.
o\bop\bpt\bti\bio\bon\bn t\btc\bcp\bp-\b-k\bke\bee\bep\bpa\bal\bli\biv\bve\be-\b-i\bin\bnt\bte\ber\brv\bva\bal\bl _\bu_\bi_\bn_\bt_\b3_\b2;\b;
- This option specifies the interval (in seconds) that the
- client TCP should wait before sending a keepalive message
- on a TCP connection. The time is specified as a 32-bit
- unsigned integer. A value of zero indicates that the
- client should not generate keepalive messages on connec-
+ This option specifies the interval (in seconds) that the
+ client TCP should wait before sending a keepalive message
+ on a TCP connection. The time is specified as a 32-bit
+ unsigned integer. A value of zero indicates that the
+ client should not generate keepalive messages on connec-
tions unless specifically requested by an application.
o\bop\bpt\bti\bio\bon\bn t\btc\bcp\bp-\b-k\bke\bee\bep\bpa\bal\bli\biv\bve\be-\b-g\bga\bar\brb\bba\bag\bge\be _\bf_\bl_\ba_\bg;\b;
This option specifies the whether or not the client should
- send TCP keepalive messages with a octet of garbage for
- compatibility with older implementations. A value of 0
+ send TCP keepalive messages with a octet of garbage for
+ compatibility with older implementations. A value of 0
indicates that a garbage octet should not be sent. A value
of 1 indicates that a garbage octet should be sent.
o\bop\bpt\bti\bio\bon\bn n\bni\bis\bs-\b-d\bdo\bom\bma\bai\bin\bn _\bs_\bt_\br_\bi_\bn_\bg;\b;
- This option specifies the name of the client's NIS (Sun
- Network Information Services) domain. The domain is for-
- matted as a character string consisting of characters from
- the NVT ASCII character set.
-
- o\bop\bpt\bti\bio\bon\bn n\bni\bis\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
-
- This option specifies a list of IP addresses indicating
- NIS servers available to the client. Servers should be
-
16
dhcpd.conf(5) dhcpd.conf(5)
+ This option specifies the name of the client's NIS (Sun
+ Network Information Services) domain. The domain is for-
+ matted as a character string consisting of characters from
+ the NVT ASCII character set.
+
+ o\bop\bpt\bti\bio\bon\bn n\bni\bis\bs-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
+
+ This option specifies a list of IP addresses indicating
+ NIS servers available to the client. Servers should be
listed in order of preference.
o\bop\bpt\bti\bio\bon\bn n\bnt\btp\bp-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of IP addresses indicating
- NTP (RFC 1035) servers available to the client. Servers
+ This option specifies a list of IP addresses indicating
+ NTP (RFC 1035) servers available to the client. Servers
should be listed in order of preference.
- o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
+ o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-n\bna\bam\bme\be-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ...
];\b;
- The NetBIOS name server (NBNS) option specifies a list of
+ The NetBIOS name server (NBNS) option specifies a list of
RFC 1001/1002 NBNS name servers listed in order of prefer-
ence.
o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-d\bdd\bd-\b-s\bse\ber\brv\bve\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- The NetBIOS datagram distribution server (NBDD) option
- specifies a list of RFC 1001/1002 NBDD servers listed in
+ The NetBIOS datagram distribution server (NBDD) option
+ specifies a list of RFC 1001/1002 NBDD servers listed in
order of preference.
o\bop\bpt\bti\bio\bon\bn n\bne\bet\btb\bbi\bio\bos\bs-\b-n\bno\bod\bde\be-\b-t\bty\byp\bpe\be _\bu_\bi_\bn_\bt_\b8;\b;
- The NetBIOS node type option allows NetBIOS over TCP/IP
- clients which are configurable to be configured as
- described in RFC 1001/1002. The value is specified as a
+ The NetBIOS node type option allows NetBIOS over TCP/IP
+ clients which are configurable to be configured as
+ described in RFC 1001/1002. The value is specified as a
single octet which identifies the client type. A value of
- 1 corresponds to a NetBIOS B-node; a value of 2 corre-
+ 1 corresponds to a NetBIOS B-node; a value of 2 corre-
sponds to a P-node; a value of 4 corresponds to an M-node;
a value of 8 corresponds to an H-node.
The NetBIOS scope option specifies the NetBIOS over TCP/IP
scope parameter for the client as specified in RFC
- 1001/1002. See RFC1001, RFC1002, and RFC1035 for charac-
+ 1001/1002. See RFC1001, RFC1002, and RFC1035 for charac-
ter-set restrictions.
o\bop\bpt\bti\bio\bon\bn f\bfo\bon\bnt\bt-\b-s\bse\ber\brv\bve\ber\brs\bs _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of X Window System Font
- servers available to the client. Servers should be listed
+ This option specifies a list of X Window System Font
+ servers available to the client. Servers should be listed
in order of preference.
o\bop\bpt\bti\bio\bon\bn x\bx-\b-d\bdi\bis\bsp\bpl\bla\bay\by-\b-m\bma\ban\bna\bag\bge\ber\br _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs [,\b, _\bi_\bp_\b-_\ba_\bd_\bd_\br_\be_\bs_\bs ... ];\b;
- This option specifies a list of systems that are running
- the X Window System Display Manager and are available to
- the client. Addresses should be listed in order of pref-
- erence.
-
- o\bop\bpt\bti\bio\bon\bn d\bdh\bhc\bcp\bp-\b-c\bcl\bli\bie\ben\bnt\bt-\b-i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br _\bd_\ba_\bt_\ba_\b-_\bs_\bt_\br_\bi_\bn_\bg;\b;
-
- This option can be used to specify the a DHCP client
-
17
dhcpd.conf(5) dhcpd.conf(5)
- identifier in a host declaration, so that dhcpd can find
- the host record by matching against the client identifier.
+ This option specifies a list of systems that are running
+ the X Window System Display Manager and are available to
+ the client. Addresses should be listed in order of pref-
+ erence.
+
+ o\bop\bpt\bti\bio\bon\bn d\bdh\bhc\bcp\bp-\b-c\bcl\bli\bie\ben\bnt\bt-\b-i\bid\bde\ben\bnt\bti\bif\bfi\bie\ber\br _\bd_\ba_\bt_\ba_\b-_\bs_\bt_\br_\bi_\bn_\bg;\b;
+
+ This option can be used to specify the a DHCP client iden-
+ tifier in a host declaration, so that dhcpd can find the
+ host record by matching against the client identifier.
S\bSE\bEE\bE A\bAL\bLS\bSO\bO
dhcpd.conf(5), dhcpd.leases(5), draft-ietf-dhc-
-
-
-
-
-
-
-
-
projects / thirdparty / dhcp.git / commitdiff
