I am trying to setup Ubuntu 11.04.
My first Project is to get nat working so that I can setup a internal network. Each Client being able to access the web. Later, if I can get that working, I hope to move on to DNS and a Web Server.

Config.

A dedicated server with 2 Ethernet cards.

DSL Fast access.

16 port hub.

4 port Wireless routers.

4 clients, 2 Vista Ult, 2 Windows 7.
Network Printer.

Local printer that will be attached to the server.

I followed 2 different approaches. Neither worked. Going to reinstall Ubuntu 11.04 Cleanly, and try, try again.

Any help here?

Can you provide more information about your setup? Are the windows clients wired/wireless? Do you want all internet access routed through the server, or will the clients connect directly to the wireless router?

All Clients are wired

I have the same problem on Debian squeeze. All the HOWTOs say it is very simple - I've tried a bunch of them but there seems to be a Debian-specific problem that prevents it from working. The first packet does go through but after that - ping says 'target network is inaccessible'.