How to create a router with my mac pro?

[fairnymph]

I have a mac pro with 2 network cards.

I have a modem with ONE ethernet out.

I need a router, in order for my TiVo to be online constantly/whenever it desires to check for program info (I do not have a landline).

I do not want to buy a router.

I have heard that I can somehow rig my MP to act as a router. Is this true, and if so, how do I do it? Googling reveals nothing of use, searching here reveals nothing of use.

Please help before I kill myself or my cat or possibly do some sort of joint massacre in honour of Hale-Bopp.

 

[apfhex]

System Preferences -> Sharing -> Internet Sharing. Share you connection from whatever port your modem is connected to, to whichever port(s) you want to use, including wireless. A search of these forums would reveal this question asked really, really often.