R: DNS dynamic update with DHCPD 3.1.3

[Glenn Satchell]

>Date: Thu, 7 Jan 2010 09:15:46 +0100
>From: "Autuori Gianluigi" <Autuori.Gianluigi.Wintime at ansaldobreda.it>
>
>Thank you,
>these are lines of my dhcpd.conf
>
>ddns-update-style interim;
>
>key DHCP_UPDATER {
>    algorithm hmac-md5;
>    secret pRP5FapFoJ95JEL06sv4PQ==;
>};
>
>zone localtrain. {
>    primary 127.0.0.1;
>    key DHCP_UPDATER;    
>}
>
>update-static-leases on;
>
>
>and these one from named.conf.local
>
>key DHCP_UPDATER {
>    algorithm hmac-md5;
>    secret pRP5FapFoJ95JEL06sv4PQ==;
>};
>
>zone "localtrain" {
>    type master;
>    file "/etc/bind/db.train.com";
>    allow-update { key DHCP_UPDATER; };
>}; 
>
>after then I restarted dhcpd and bind9 but db.train.com doesn't change.
>
>what is wrong?
>
>-----Messaggio originale-----
>Da: dhcp-users-bounces+autuori.gianluigi.wintime=ansaldobreda.it at lists.isc.org 
[mailto:dhcp-users-bounces+autuori.gianluigi.wintime=ansaldobreda.it at lists.isc.o
rg] Per conto di Simon Hobson
>Inviato: martedì 5 gennaio 2010 15.37
>A: Users of ISC DHCP
>Oggetto: Re: DNS dynamic update with DHCPD 3.1.3
>
>Autuori Gianluigi wrote:
>>I configured dhcp server and now I want to update database of dns
>>(BIND9) every time dhcp server assigns an ip to  new device.
>>how can I do it?
>
>Start with 'man dhcpd.conf' and see the section on dynamic DNS updating. It's 
quite easy to set up - but be careful about the subtle differences in use of 
quotes between dpcdp and bind.
>
>If, when you've read the man pages, there is anything you don't understand, or 
if it's not working properly, then pop back here and we'll be happy to help.
>

The syntax you have included seems to be ok.

Ok, a few things to try:

Did you restart bind and dhcpd after updating the files? Were there any
warnings or errors from the startup?

If you use nsupdate and that key can you update the zone file?  If so
then this eliminates the key and the update mechanism.

Turn on logging for bind to see if there are any updates coming through
and being dropped. By default bind will silently ignore any updates if
there is something not right in the configuration

Is there anything in the dhcp syslog output indicating an attempt at
updating DNS?

The key you included is from the dhcpd.conf file. I am not sure if that
is a valid key, so you may want to generate a new key.

Usually it is something "odd" about your environment that causes
problems. Typically this should "just work".

regards,
-glenn