Internet Sharing and issues in iChat and Mail

[GeeYouEye]

Hopefully a quick question: I'm trying to use Internet Sharing from an iMac's AirPort-to-built-in-Ethernet to another computer's ethernet port. Browsing the web works fine, but for some reason, iChat and Mail don't work on the second computer. iChat will open and create a Rendezvous/Bonjour session, but AIM doesn't work. Mail won't get messages (from a .mac or ISP account); the connection times out. Anyone know a workaround for this? Running 10.4.1, but the problem existed back in 10.3.

I suspect it has something to do with a second layer of NAT'ing, but I could be completely off there.

 

[croshtique]

I've had similar problems and traced it to the firewall on the 'host' computer - either turn off the firewall or just manually open the required ports for email/AIM in Sharing prefs.