Date: 28-11-00 21:46
if your ip is aaa.bbb.ccc.ddd and your friends ip is eee.fff.ggg.hhh then you would do the following as root:
ipfw add allow ip from aaa.bbb.ccc.ddd to eee.fff.ggg.hhh
ipfw add allow ip from eee.fff.ggg.hhh to aaa.bbb.ccc.ddd
That will open ALL ip traffic to and from your friend.
You could also just open port 21 for your friend. To do that you would do:
ipfw add allow tcp from any to any established
ipfw add allow tcp from eee.fff.ggg.hhh to aaa.bbb.ccc.ddd 21 in setup