[master]

Remove outdated section on ad-hoc DDNS
[ISC-Bugs #21798 #29939]

diff --git a/common/dhcp-eval.5 b/common/dhcp-eval.5
index 4a017d9fc85358dab3e175f676c02c3622aee77d..c9ad689bb144117a4939aac331470c17ba398d8f 100644 (file)
--- a/common/dhcp-eval.5
+++ b/common/dhcp-eval.5
@@ -497,50 +497,8 @@ you will execute that command every time a scope is evaluated.
 .RE
 .SH REFERENCE: DYNAMIC DNS UPDATES
 .PP
-The DHCP client and server have the ability to dynamically update the
-Domain Name System.  Within the configuration files, you can define
-how you want the Domain Name System to be updated.  These updates are
-RFC 2136 compliant so any DNS server supporting RFC 2136 should be
-able to accept updates from the DHCP server.
-.SH SECURITY
-Support for TSIG and DNSSEC is not yet available.  When you set your
-DNS server up to allow updates from the DHCP server or client, you may
-be exposing it to unauthorized updates.  To avoid this, the best you
-can do right now is to use IP address-based packet filtering to
-prevent unauthorized hosts from submitting update requests.
-Obviously, there is currently no way to provide security for client
-updates - this will require TSIG or DNSSEC, neither of which is yet
-available in the DHCP distribution.
-.PP
-Dynamic DNS (DDNS) updates are performed by using the \fBdns-update\fR
-expression.  The \fBdns-update\fR expression is a boolean expression
-that takes four parameters.  If the update succeeds, the result is
-true.  If it fails, the result is false.  The four parameters that the
-are the resource record type (RR), the left hand side of the RR, the
-right hand side of the RR and the ttl that should be applied to the
-record.  The simplest example of the use of the function can be found
-in the reference section of the dhcpd.conf file, where events are
-described.  In this example several statements are being used to make
-the arguments to the \fBdns-update\fR.
-.PP
-In the example, the first argument to the first \f\Bdns-update\fR
-expression is a data expression that evaluates to the A RR type.  The
-second argument is constructed by concatenating the DHCP host-name
-option with a text string containing the local domain, in this case
-"ssd.example.net".  The third argument is constructed by converting
-the address the client has been assigned from a 32-bit number into an
-ascii string with each byte separated by a ".".  The fourth argument,
-the TTL, specifies the amount of time remaining in the lease (note
-that this isn't really correct, since the DNS server will pass this
-TTL out whenever a request comes in, even if that is only a few
-seconds before the lease expires).
-.PP
-If the first \fBdns-update\fR statement succeeds, it is followed up
-with a second update to install a PTR RR.  The installation of a PTR
-record is similar to installing an A RR except that the left hand side
-of the record is the leased address, reversed, with ".in-addr.arpa"
-concatenated.  The right hand side is the fully qualified domain name
-of the client to which the address is being leased.
+See the dhcpd.conf and dhclient.conf man pages for more information
+about DDNS.
 .SH SEE ALSO
 dhcpd.conf(5), dhcpd.leases(5), dhclient.conf(5), dhcp-options(5), dhcpd(8),
 dhclient(8), RFC2132, RFC2131.