Baffling DNS from a DHCP server problem. Appears to be ignoring dhcp.conf
 

I have a linux mint xfce 8 (compatable with Ubuntu Intrepid) box that serves DHCP and forwards its internet connection through firestarter.
The actual IP is served corectly, the problem I'm having is with the DNS that it gives out that is then stored in the clients resolv.conf

The servers dhcp.conf has the line :
option domain-name-servers 203.52.100.13;

However, the clients recive the number:
203.52.122.13

I have changed the dhcp.conf to serve the number 203.52.112.13 (which would also work), but the clients are still reciving 203.52.122.13

Thinking that I might have made a mistake while writing it by hand, I got firestarter to write me a new dhcp.conf which looks almost the same as mine, but the clients continue to recive the wrong number.

This behaviour continues after restarting the demon and even rebooting.
I have googled looking for other sources of configuration for the servers DHCP, but they all refer to dhcp.conf

Can any one make a sugestion as to how to find the source of this problem?

You have to review your daemon logs very carefuly, I have a post entry on how to do that.

http://soad1982.blogspot.com/2010/02...t-daemons.html

What you should at least make sure for instance is the DHCPREQUEST and DHCPACK via you logs, maybe you have a host based definition, if you could include your settings will be useful, I wrote how to create a fast DHCP maybe you just need a fresh start. DHCP Howto

For example an output delivering DHCP information should look like:

Feb 15 10:03:22 debian dhcpd: DHCPREQUEST for 172.16.32.12 from 00:21:70:9b:da:fa via eth3
Feb 15 10:03:22 debian dhcpd: DHCPACK on 172.16.32.12 to 00:21:70:9b:da:fa via eth3

Just match the MAC address and make sure you're the one giving the IP address.