Network Bridging / Internet Connection Sharing in Ubuntu

[CalcProgrammer1]

Well, I have my ThinkPad A21p running both Windows XP Home and Ubuntu 7.10 (soon 8.04).

The only thing I use Windows for (seriously, it's like the only time I ever boot Windows on this PC) is using my laptop as an Ethernet - WiFi bridge for playing my Xbox 360 in my living room.

However, I also sometimes play with my friend, where I hook my laptop to my Ethernet switch, then hook two Xbox 360's to the switch, both 360's can use the laptop's Internet to go online. I use Windows XP's Internet Connection Sharing feature to do this.

So, I'm thinking about making this an Ubuntu-only PC with 8.04, and considering the only thing I use XP for is ICS, I'm wondering how I could do the same thing in Linux. My PC has two PCMCIA (CardBus) slots, one with a 54g Broadcom-based Buffalo WLI-CB-G54S WiFi card and the other with a D-Link Ethernet PCMCIA 10/100 card. "Network" under Administration shows three connections, "Wired" (set to roaming mode), "Wireless" (also set to roaming mode), and "Modem" (not configured, don't use dial-up). I want to bridge Wireless and Wired. Wireless will be the one with the Internet connection and Wired needs to provide Internet to the Xbox (or two Xboxes). How do you go about doing this in Linux?

[nitestick]

you should be able to do this using NAT and dnsmasq, to provide NAT from your internet connection to a specified interface. i'm currently running something like this to share dialup to my laptop via an Ethernet connection. i don't really know what i'm doing when setting up NAT (on a pc) to be perfectly honest and i've used a guide each time.

try googling: NAT internet sharing linux
or something like that.