I am trying to get a linux host (Ubuntu 9.10) through a Cisco Pix Firewall. I have set up the appropriate Firewall Rule to allow through and have gone with the default dynamic NAT settings and have used as the subnet mask. When it comes to configuring the linuxbox I configure eth0 to use static ip: (this is where my not so brilliant knowledge of networking comes in) and have set sub net mask to and linuxbox connects when ethernet cable plugs in but clearly is not being allowed to pass through the firewall. P.S I have entered DNS IP settings in addition. If anything I think the subnet mask must be wrong. Also when I first plugged in ethernet cable I got an Avahi disabled due to .internal domain name message (don't think this is the problem as I have tried using a windows machine with same settings to no avail.

Please Help,