.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.Dd March 19, 20122
-.Dt DHCPCD 8 SMM
+.Dd March 19, 2012
+.Dt DHCPCD 8
.Os
.Sh NAME
.Nm dhcpcd
.Nd an RFC 2131 compliant DHCP client
.Sh SYNOPSIS
.Nm
-.Op Fl bdgknpqwABDEGHJKLTV
-.Op Fl c , -script Ar script
-.Op Fl e , -env Ar value
-.Op Fl f , -config Ar file
-.Op Fl h , -hostname Ar hostname
-.Op Fl i , -vendorclassid Ar vendorclassid
-.Op Fl l , -leasetime Ar seconds
-.Op Fl m , -metric Ar metric
-.Op Fl o , -option Ar option
-.Op Fl r , -request Ar address
-.Op Fl s , -inform Ar address Ns Op Ar /cidr
-.Op Fl t , -timeout Ar seconds
-.Op Fl u , -userclass Ar class
-.Op Fl v , -vendor Ar code , Ar value
-.Op Fl y , -reboot Ar seconds
-.Op Fl z , -allowinterfaces Ar pattern
-.Op Fl C , -nohook Ar hook
-.Op Fl F , -fqdn Ar FQDN
-.Op Fl I , -clientid Ar clientid
-.Op Fl O , -nooption Ar option
-.Op Fl Q , -require Ar option
-.Op Fl S , -static Ar value
-.Op Fl W , -whitelist Ar address Ns Op Ar /cidr
-.Op Fl X , -blacklist Ar address Ns Op Ar /cidr
-.Op Fl Z , -denyinterfaces Ar pattern
+.Op Fl ABbDdEGgHJKkLnpqTVw
+.Op Fl C , Fl Fl nohook Ar hook
+.Op Fl c , Fl Fl script Ar script
+.Op Fl e , Fl Fl env Ar value
+.Op Fl F , Fl Fl fqdn Ar FQDN
+.Op Fl f , Fl Fl config Ar file
+.Op Fl h , Fl Fl hostname Ar hostname
+.Op Fl I , Fl Fl clientid Ar clientid
+.Op Fl i , Fl Fl vendorclassid Ar vendorclassid
+.Op Fl l , Fl Fl leasetime Ar seconds
+.Op Fl m , Fl Fl metric Ar metric
+.Op Fl O , Fl Fl nooption Ar option
+.Op Fl o , Fl Fl option Ar option
+.Op Fl Q , Fl Fl require Ar option
+.Op Fl r , Fl Fl request Ar address
+.Op Fl S , Fl Fl static Ar value
+.Op Fl s , Fl Fl inform Ar address Ns Op Ar /cidr
+.Op Fl t , Fl Fl timeout Ar seconds
+.Op Fl u , Fl Fl userclass Ar class
+.Op Fl v , Fl Fl vendor Ar code , Ar value
+.Op Fl W , Fl Fl whitelist Ar address Ns Op Ar /cidr
+.Op Fl y , Fl Fl reboot Ar seconds
+.Op Fl X , Fl Fl blacklist Ar address Ns Op Ar /cidr
+.Op Fl Z , Fl Fl denyinterfaces Ar pattern
+.Op Fl z , Fl Fl allowinterfaces Ar pattern
.Op interface
.Op ...
.Nm
-.Fl k , -release
+.Fl k , Fl Fl release
.Op interface
.Nm
-.Fl U, -dumplease
+.Fl U, Fl Fl dumplease
.Ar interface
.Nm
-.Fl x , -exit
-.Op interface
+.Fl Fl version
.Nm
-.Fl v , -version
+.Fl x , Fl Fl exit
+.Op interface
.Sh DESCRIPTION
.Nm
is an implementation of the DHCP client specified in
In the rare case it fails, it normally means that there is a reverse ARP proxy
installed which always defeats IPv4LL probing.
To disable this behaviour, you can use the
-.Fl L , -noipv4ll
+.Fl L , Fl Fl noipv4ll
option.
.Ss Multiple interfaces
If a list of interfaces are given on the command line, then
will try and obtain a lease before forking to the background,
otherwise it will fork right away.
This behaviour can be modified with the
-.Fl b , -background
+.Fl b , Fl Fl background
and
-.Fl w , -waitip
+.Fl w , Fl Fl waitip
options.
.Pp
If a single interface is given then
.Nm
only works for that interface and runs as a separate instance.
The
-.Fl w , -waitip
+.Fl w , Fl Fl waitip
option is enabled in this instance to maintain compatibility with older
versions.
.Pp
runs
.Pa @SCRIPT@ ,
or the script specified by the
-.Fl c , -script
+.Fl c , Fl Fl script
option.
This script runs each script found in
.Pa @HOOKDIR@
and
.Pa 30-hostname .
You can disable each script by using the
-.Fl C , -nohook
+.Fl C , Fl Fl nohook
option.
See
.Xr dhcpcd-run-hooks 8
.Nm
with the following options:
.Bl -tag -width indent
-.It Fl b , -background
+.It Fl b , Fl Fl background
Background immediately.
This is useful for startup scripts which don't disable link messages for
carrier status.
-.It Fl c , -script Ar script
+.It Fl c , Fl Fl script Ar script
Use this
.Ar script
instead of the default
.Pa @SCRIPT@ .
-.It Fl d , -debug
+.It Fl D , Fl Fl duid
+Generate an
+.Li RFC 4361
+compliant clientid.
+This requires persistent storage and not all DHCP servers work with it so it
+is not enabled by default.
+.Nm
+generates the DUID and stores it in
+.Pa @SYSCONFDIR@/dhcpcd.duid .
+This file should not be copied to other hosts.
+.It Fl d , Fl Fl debug
Echo debug messages to the stderr and syslog.
-.It Fl e , -env Ar value
+.It Fl E , Fl Fl lastlease
+If
+.Nm
+cannot obtain a lease, then try to use the last lease acquired for the
+interface.
+If the
+.Fl p, Fl Fl persistent
+option is not given then the lease is used if it hasn't expired.
+.It Fl e , Fl Fl env Ar value
Push
.Ar value
to the environment for use in
For example, you can force the hostname hook to always set the hostname with
.Fl e
.Va force_hostname=YES .
-.It Fl g , -reconfigure
+.It Fl g , Fl Fl reconfigure
.Nm
will re-apply IP address, routing and run
.Xr dhcpcd-run-hooks 8
.Nm
does not read a new configuration when this happens - you should rebind if you
need that functionality.
-.It Fl f , -config Ar file
+.It Fl F , Fl Fl fqdn Ar fqdn
+Requests that the DHCP server updates DNS using FQDN instead of just a
+hostname.
+Valid values for
+.Ar fqdn
+are disable, none, ptr and both.
+.Nm
+itself never does any DNS updates.
+.Nm
+encodes the FQDN hostname as specified in
+.Li RFC1035 .
+.It Fl f , Fl Fl config Ar file
Specify a config to load instead of
.Pa @SYSCONFDIR@/dhcpcd.conf .
.Nm
always processes the config file before any command line options.
-.It Fl h , -hostname Ar hostname
+.It Fl h , Fl Fl hostname Ar hostname
Sends
.Ar hostname
to the DHCP server so it can be registered in DNS.
If
.Ar hostname
is a FQDN (ie, contains a .) then it will be encoded as such.
-.It Fl i , -vendorclassid Ar vendorclassid
+.It Fl I , Fl Fl clientid Ar clientid
+Send the
+.Ar clientid .
+If the string is of the format 01:02:03 then it is encoded as hex.
+For interfaces whose hardware address is longer than 8 bytes, or if the
+.Ar clientid
+is an empty string then
+.Nm
+sends a default
+.Ar clientid
+of the hardware family and the hardware address.
+.It Fl i , Fl Fl vendorclassid Ar vendorclassid
Override the
.Ar vendorclassid
-field sent. The default is
+field sent.
+The default is
dhcpcd <version>.
If not set then none is sent.
-.It Fl k , -release
+.It Fl k , Fl Fl release
This causes an existing
.Nm
process running on the
and then exit.
.Nm
then waits until this process has exited.
-.It Fl l , -leasetime Ar seconds
+.It Fl l , Fl Fl leasetime Ar seconds
Request a specific lease time in
.Ar seconds .
By default
.Nm
does not request any lease time and leaves it in the hands of the
DHCP server.
-.It Fl m , -metric Ar metric
+.It Fl m , Fl Fl metric Ar metric
Metrics are used to prefer an interface over another one, lowest wins.
.Nm
will supply a default metic of 200 +
.Xr if_nametoindex 3 .
An extra 100 will be added for wireless interfaces.
-.It Fl o , -option Ar option
-Request the DHCP
-.Ar option
-variable for use in
-.Pa @SCRIPT@ .
-.It Fl n , -rebind
+.It Fl n , Fl Fl rebind
Notifies
.Nm
to reload its configuration and rebind its interfaces.
If
.Nm
is not running, then it starts up as normal.
-.It Fl p , -persistent
+.It Fl o , Fl Fl option Ar option
+Request the DHCP
+.Ar option
+variable for use in
+.Pa @SCRIPT@ .
+.It Fl p , Fl Fl persistent
.Nm
normally de-configures the
.Ar interface
Sometimes, this isn't desirable if, for example, you have root mounted over
NFS.
You can use this option to stop this from happening.
-.It Fl r , -request Op Ar address
+.It Fl r , Fl Fl request Op Ar address
Request the
.Ar address
in the DHCP DISCOVER message.
is given then the first address currently assigned to the
.Ar interface
is used.
-.It Fl s , -inform Op Ar address Ns Op Ar /cidr
+.It Fl s , Fl Fl inform Op Ar address Ns Op Ar /cidr
Behaves like
-.Fl r , -request
+.Fl r , Fl Fl request
as above, but sends a DHCP INFORM instead of DISCOVER/REQUEST.
This does not get a lease as such, just notifies the DHCP server of the
.Ar address
.Nm
fails to contact a DHCP server then it returns a failure instead of falling
back on IPv4LL.
-.It Fl t , -timeout Ar seconds
+.It Fl t , Fl Fl timeout Ar seconds
Timeout after
.Ar seconds ,
instead of the default 30.
causes
.Nm
to wait forever to get a lease.
-.It Fl u , -userclass Ar class
+.It Fl u , Fl Fl userclass Ar class
Tags the DHCP message with the userclass
.Ar class .
DHCP servers use this to give members of the class DHCP options other than the
default, without having to know things like hardware address or hostname.
-.It Fl v , -vendor Ar code , Ns Ar value
+.It Fl v , Fl Fl vendor Ar code , Ns Ar value
Add an encapsulated vendor option.
.Ar code
should be between 1 and 254 inclusive.
.D1 dhcpcd \-v 03,\e"192.168.0.2\e" eth0
Set un-encapsulated vendor option to hello world.
.D1 dhcpcd \-v ,"hello world" eth0
-.It Fl v , -version
+.It Fl Fl version
Display both program version and copyright information.
.Nm
then exits before doing any configuration.
-.It Fl w , -waitip
+.It Fl w , Fl Fl waitip
Wait for an address to be assigned before forking to the background.
-.It Fl x , -exit
+.It Fl x , Fl Fl exit
This will signal an existing
.Nm
process running on the
and exit.
.Nm
then waits until this process has exited.
-.It Fl y , -reboot Ar seconds
+.It Fl y , Fl Fl reboot Ar seconds
Allow
.Ar reboot
seconds before moving to the discover phase if we have an old lease to use.
A setting of 0 seconds causes
.Nm
to skip the reboot phase and go straight into discover.
-.It Fl D , -duid
-Generate an
-.Li RFC 4361
-compliant clientid.
-This requires persistent storage and not all DHCP servers work with it so it
-is not enabled by default.
-.Nm
-generates the DUID and stores it in
-.Pa @SYSCONFDIR@/dhcpcd.duid .
-This file should not be copied to other hosts.
-.It Fl E , -lastlease
-If
-.Nm
-cannot obtain a lease, then try to use the last lease acquired for the
-interface.
-If the
-.Fl p, -persistent
-option is not given then the lease is used if it hasn't expired.
-.It Fl F , -fqdn Ar fqdn
-Requests that the DHCP server updates DNS using FQDN instead of just a
-hostname.
-Valid values for
-.Ar fqdn
-are disable, none, ptr and both.
-.Nm
-itself never does any DNS updates.
-.Nm
-encodes the FQDN hostname as specified in
-.Li RFC1035 .
-.It Fl I , -clientid Ar clientid
-Send the
-.Ar clientid .
-If the string is of the format 01:02:03 then it is encoded as hex.
-For interfaces whose hardware address is longer than 8 bytes, or if the
-.Ar clientid
-is an empty string then
-.Nm
-sends a default
-.Ar clientid
-of the hardware family and the hardware address.
.El
.Ss Restricting behaviour
.Nm
configured exactly how the the DHCP server wants.
Here are some options that deal with turning these bits off.
.Bl -tag -width indent
-.It Fl q , -quiet
-Quiet
-.Nm
-on the command line, only warnings and errors will be displayed.
-The messages are still logged though.
-.It Fl z , -allowinterfaces Ar pattern
-When discovering interfaces, the interface name must match
-.Ar pattern
-which is a space or comma separated list of patterns passed to
-.Xr fnmatch 3 .
-If the same interface is matched in
-.Fl Z , -denyinterfaces
-then it is still denied.
-.It Fl A , -noarp
+.It Fl A , Fl Fl noarp
Don't request or claim the address by ARP.
This also disables IPv4LL.
-.It Fl B , -nobackground
+.It Fl B , Fl Fl nobackground
Don't run in the background when we acquire a lease.
This is mainly useful for running under the control of another process, such
as a debugger or a network manager.
-.It Fl C , -nohook Ar script
+.It Fl C , Fl Fl nohook Ar script
Don't run this hook script.
Matches full name, or prefixed with 2 numbers optionally ending with
.Pa .sh .
.Nm
from touching your DNS or MTU settings you would do:-
.D1 dhcpcd -C resolv.conf -C mtu eth0
-.It Fl G , -nogateway
+.It Fl G , Fl Fl nogateway
Don't set any default routes.
-.It Fl H , -xidhwaddr
+.It Fl H , Fl Fl xidhwaddr
Use the last four bytes of the hardware address as the DHCP xid instead
of a randomly generated number.
-.It Fl J , -broadcast
+.It Fl J , Fl Fl broadcast
Instructs the DHCP server to broadcast replies back to the client.
Normally this is only set for non Ethernet interfaces,
such as FireWire and InfiniBand.
In most instances,
.Nm
will set this automatically.
-.It Fl K , -nolink
+.It Fl K , Fl Fl nolink
Don't receive link messages for carrier status.
You should only have to use this with buggy device drivers or running
.Nm
through a network manager.
-.It Fl L , -noipv4ll
+.It Fl L , Fl Fl noipv4ll
Don't use IPv4LL (aka APIPA, aka Bonjour, aka ZeroConf).
-.It Fl O , -nooption Ar option
+.It Fl O , Fl Fl nooption Ar option
Don't request the specified option.
If no option given, then don't request any options other than those to
configure the interface and routing.
-.It Fl Q , -require Ar option
+.It Fl Q , Fl Fl require Ar option
Requires the
.Ar option
to be present in all DHCP messages, otherwise the message is ignored.
only responds to DHCP servers and not BOOTP servers, you can
.Fl Q
.Ar dhcp_message_type .
-.It Fl S, -static Ar value
+.It Fl q , Fl Fl quiet
+Quiet
+.Nm
+on the command line, only warnings and errors will be displayed.
+The messages are still logged though.
+.It Fl S, Fl Fl static Ar value
Configures a static
.Ar value .
If you set
.D1 -S routers=192.168.0.1 \e
.D1 -S domain_name_servers=192.168.0.1 \e
.D1 eth0
-.It Fl T, -test
+.It Fl T, Fl Fl test
On receipt of DHCP messages just call
.Pa @SCRIPT@
with the reason of TEST which echos the DHCP variables found in the message
To test INFORM the interface needs to be configured with the desired address
before starting
.Nm .
-.It Fl U, -dumplease Ar interface
+.It Fl U, Fl Fl dumplease Ar interface
Dumps the last lease for the
.Ar interface
to stdout.
.Ar interface
could also be a path to a DHCP wire formatted file.
-.It Fl V, -variables
+.It Fl V, Fl Fl variables
Display a list of option codes and the associated variable for use in
.Xr dhcpcd-run-hooks 8 .
Variables are prefixed with new_ and old_ unless the option number is -.
Variables without an option are part of the DHCP message and cannot be
directly requested.
-.It Fl W, -whitelist Ar address Ns Op /cidr
+.It Fl W, Fl Fl whitelist Ar address Ns Op /cidr
Only accept packets from
.Ar address Ns Op /cidr .
-.Fl X, -blacklist
+.Fl X, Fl Fl blacklist
is ignored if
-.Fl W, -whitelist
+.Fl W, Fl Fl whitelist
is set.
-.It Fl X, -blacklist Ar address Ns Op Ar /cidr
+.It Fl X, Fl Fl blacklist Ar address Ns Op Ar /cidr
Ignore all packets from
.Ar address Ns Op Ar /cidr .
-.It Fl Z , -denyinterfaces Ar pattern
+.It Fl Z , Fl Fl denyinterfaces Ar pattern
When discovering interfaces, the interface name must not match
.Ar pattern
which is a space or comma separated list of patterns passed to
.Xr fnmatch 3 .
+.It Fl z , Fl Fl allowinterfaces Ar pattern
+When discovering interfaces, the interface name must match
+.Ar pattern
+which is a space or comma separated list of patterns passed to
+.Xr fnmatch 3 .
+If the same interface is matched in
+.Fl Z , Fl Fl denyinterfaces
+then it is still denied.
.El
.Sh 3RDPARTY LINK MANAGEMENT
Some interfaces require configuration by 3rd parties, such as PPP or VPN.
.It Pa @HOOKDIR@
A directory containing bourne shell scripts that are run by the above script.
Each script can be disabled by using the
-.Fl C , -nohook
+.Fl C , Fl Fl nohook
option described above.
.It Pa @DBDIR@/dhcpcd\- Ns Ar interface Ns .lease
-The actual DHCP message send by the server. We use this when reading the last
+The actual DHCP message send by the server.
+We use this when reading the last
lease and use the files mtime as when it was issued.
.It Pa /var/run/dhcpcd.pid
Stores the PID of
.Ar interface .
.El
.Sh SEE ALSO
+.Xr fnmatch 3 ,
+.Xr if_nametoindex 3 ,
.Xr dhcpcd.conf 5 ,
-.Xr dhcpcd-run-hooks 8 ,
.Xr resolv.conf 5 ,
-.Xr resolvconf 8 ,
-.Xr if_nametoindex 3 ,
-.Xr fnmatch 3
+.Xr dhcpcd-run-hooks 8 ,
+.Xr resolvconf 8
.Sh STANDARDS
RFC 951, RFC 1534, RFC 2131, RFC 2132, RFC 2855, RFC 3004, RFC 3361, RFC 3396,
RFC 3397, RFC 3442, RFC 3927, RFC 4361, RFC 4390, RFC 4702, RFC 5969, RFC 6106.
projects / thirdparty / dhcpcd.git / commitdiff
