dhclient complains Can't update forward map no such RRset

Glenn Satchell Glenn.Satchell at uniq.com.au
Sun Mar 26 23:46:30 UTC 2006

Hi Noah,

dhclient is the *client* side of dhcp, that is, the part that requests
an adddress from a server, and configures an ethernet interface.

dhcpd is the *server* that hands out the addresses, and usually is the
bit that adds things to DNS via dynamic updates.

There is a very good section in the dhcpd.conf man page on setting up
dynamic dns. It includes the sections of the config files for
dhcpd.conf and named.conf that you need to add. If you follow the
examples I am sure you will be able to get it working.

Also take note of the client-updates statement in dhcpd.conf. If you
allow client-updates then dhcpd expects the client to do the update (in
Microsoft it means tick the box "register my name in DNS"). If you
ignore client-updates the the dhcp server will do the dns updates. In
either case the dhcp server does the reverse entry to the in-add.arps


>From: "Noah" <admin2 at enabled.com>
>To: "dhclient" <dhcp-client at isc.org>
>Subject: dhclient complains Can't update forward map no such RRset
>Date: Sun, 26 Mar 2006 14:27:21 -0800
>Okay I am at a loss here and hope somebody can assist me with troubleshooting
>my current configuration issues.  I read through the man pages for dhcp, bind,
>dhclient, and relevant config files and I have not been able to find a cure to
>my issue.
>I have two servers:  the first is a server running dhclient/dhcpd that is
>sending ddns updates to a primary name server.
>dhclient is complaining:  "Mar 26 13:56:48 protect1 dhclient: Can't update
>forward map protect1.domain.com. to no such RRset" 
>I do not have a good understanding of what the above error message means
>and/or how to cure it.  What on earth am I doing wrong?
>--- snip ---
># dhclient -v
>Internet Systems Consortium DHCP Client V3.0.2-RedHat
>--- snip ---
>here is my dhclient configuration  
>---s nip ----
># cat /etc/dhclient-eth0.conf 
>send host-name "machine.hostname.com.";
>send fqdn.fqdn "machine.hostname.com.";
>send fqdn.encoded on;
>send fqdn.server-update off;
>key machine.hostname.com {
>    algorithm HMAC-MD5;
>    secret "a;dflkja;sldkfja;lkdjq;wlekjr;qlkwejr;lqkwjer;lkqjewr";
>zone hostname.com {
>    primary;
>    key "machine.hostname.com";
>interface "eth0" {
>    send host-name "machine.hostname.com.";
>    send dhcp-client-identifier 00:C0:F0:1F:21:E2;
>    send dhcp-lease-time 3600;
>    supersede domain-name "host.hostname.com hostname.com";
>    prepend domain-name-servers;
>    request subnet-mask, broadcast-address, time-offset, routers, domain-name,
>name-servers, host-name;
>    require subnet-mask, domain-name-servers;
>    script "/sbin/dhclient-script";
>---- snip ----

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