bund9 - overriding domain
 

Is there a way to configure bind so that it would "override" some domain w/o duplicating the entire zone?
E.g. got a domain somedomain.com with a number of subdomains i don't care about managed elsewhere.
Say, server.somedomain.com resolves into 195.12.08.11. Is there a way to make it resolve into 192.168.0.254 for the clients of the LAN? No fraud involved, just need to make sure services are available to LAN clients in case WAN interface (pptp link) goes down.
TIA.

Well, yeah, quite easy. Make it your secondary or tertiary DNS server via DHCP. When the WAN link goes out, your clients will try 195.12.8.11 first, timeout, and then try 192.168.0.254.

Easy as that. You can also run two "primary" servers easily enough; you just copy your zone files to each server and tell it that it's the master, authoratitive server for that zone.

Thanks for your reply.
1. It's the only dns server installed on the router. So no way.
2. I'd like to avoid duplicating zone info. Besides, this looks like a way too dirty hack ;).

Any other ideas?

WAAAAIT. . .after re-reading your post, are you saying 195.12.8.11 is the server you're using for DNS resolution, or what?

And the two ideas I gave you are the simplest. You will HAVE to duplicate zone info to serve up a DNS zone. Plain and simple. Even if you run a secondary, you're duplicating zone info. You can, however, selectively duplicate zone info. Pick up a book on BIND, preferably this one: http://www.amazon.com/DNS-BIND-5th-C...7900489&sr=1-2

The reason you have to have two primary servers is that records die off after their TTL in a slave; so if, for example, your external DNS dies (the master), the clock starts ticking on your slave DNS. After the specified time, your DNS server reaps the dead records and you're screwed. No resolution. As long as you have authority over the zone, it's not a dirty hack; it's redundancy.

Nope, that's the domain name server.somedomain.com that resolves into 195.12.8.11. The domain name is managed by external NSs that don't relate to the LAN anyhow.
I'll pick up the book you've suggested, thanks.