new server

[jack]

installed 7.10 server with LAMP, OPEN-SSH server.
After setting up fairly basic firewall rules, apt-get won't work.
In looking at dmesg, it appears that this traffic is trying to use port
53 (which I have open).
The only part I was a bit fuzzy on was in setting the input and output
for the IP address. Since I'm on a router serving DHCP, I've assigned
this machine 192.168.1.101 (which I thought worked when first tried).

So, the leading question is - which port is apt-get trying to access ?
If it is port 53, is the IP address I have in the ruleset wrong?

I can supply the ruleset if it will help (it's not very long)

Thanks for helping to clear away the cobwebs.