Can someone explain forwarders and why I don't need them?

[Alex Hulse]

I always used to think that in order for a named installed to work 
right, it'd need a forwarder to work correctly - ie, point it to the 
upstream DNS.

I noticed in this group (when searching for the answer to something else 
entirely) that you didn't need one. Odd, I thought, and removed it to 
see what'd happen. Suddenly I get much faster DNS. Huh?

However, if I removed it from a machine one firewall behind that (we 
have two networks that go Internet --dsl router-->network 1--firewall 
linux-->network 2) ie in network 2, that one ground to a halt, so I put 
it back and it worked fine again.

Really odd stuff! Any ideas?

Thanks

Alex