I have a pc which I have installed ubuntu 7.10 on and I have plugged in the LAN cable and our DHCP server has leased it an ip address:
192.168.0.x I can ping internal workstations but cannot ping the gateway (firewall - cisco pix) I have set up the firewall rule to allow from the inside interface (using the pc's ip) to the outside interface (all - 0.0.0.0) however I cannot ping the firewall which I can ping from my windows machine and cannot browse the web using firefox. I've mentioned this ordeal to a friend/collegue and she's going to have a look for me but if anyone else knows of anything please feel free to reply to this thread. If my friend can fix my problem I will post the solution up here......

well icmp can be very misleading with firewalls. if you do ping it, do you have an entry in your arp table after the failed ping has finished? that's what you should really look at to see if it's reachable or not. being able to ping other boxes really should prove that you can hit it. you're not doing anything wacky like transparent bridging through it or something like that?

We have a linux server in a DMZ as well which does have internet so I copied its firewall rule and edited the interfaces as to be inside -> outside and then edited its ip and default mask to be what it should be for the leased ip from DHCP and it now pings the gateway but still cannot ping google.com or bbc.co.uk I think i may of got the default mask wrong so tommorow I will check that.

All I had to do was to delete the rule recreate it save changes to cisco pix flash rom, then run on linux box:

ifdown eth0
ifup eth0