In the end, I followed this excellent step-by-step guide. What I would say is follow the steps exactly, make sure it’s working, then go back and amend it for your network and situation.

These are the other sites I referred to.

• http://www.aboutdebian.com/dns.htm - good guide, but following the example didn’t work.
• http://www.madboa.com/geek/soho-bind/.
• http://www.tldp.org/HOWTO/DNS-HOWTO.html

I use the DNS primarily to access machines on my LAN by name, forwarding requests to work machines to the VPN’s DNS. I’m hoping that I also see a performance improvement due to cached responses. I probably could have used dnsmasq, but I wanted to understand how bind9 worked.

A couple of gotchas;

• Make sure the format of the zone files is correct; I had excluded the hostmaster email address, which made everything fail horribly.
• Check your /etc/hosts and /etc/hostname files match your DNS setup. I didn’t; ping returned some very strange results.

UPDATE: After a couple of reboots it was clear something was wrong. The linux box itself wasn’t able to resolve names. Looking in /etc/resolv.conf showed that 127.0.0.1 i.e. itself wasn’t listed; Some process was rewriting it.

I then remembered that the linux box is set up to get its IP by DHCP (always the same as the router matches the MAC address). You need to change the dhcp client settings – take a look in /etc/dhcp3/dhclient.conf, and uncomment the line: #prepend domain-name-servers 127.0.0.1