i assume you're using a wintel variant (win98/Me/NT/2k)...
so you're gonna need to get your machine's ip address... if you use dialup or (a)dsl, that's probably a dynamic address. in win95-98/Me, from a command prompt, type “winipcfg” (i think this is the command for win98, haven't touched it in years though). in NT you type "ipconfig /all"
get your adapter's current address--that's the address you'll give to your buddy, so make note of it.
(if you're using mac, go applemenu:control panels:tcp/ip)
(if you're using linux, that's "ifconfig -a")
now launch infiltration, and from the console flick the "net war" toggle and set up whatever rules/maps/options you want.
your bud should be able to right click in his inf server browser to access the "open location" command, at which time he'd enter your IP address.
if you have a LAN, and you've got a router in your LAN, you'll have to see your router's manual for details on port-forwarding... otherwise, you're done--go play!
enjoy!
