The other day, my whife came home with an "Age of Empires Collector" DVD containing AoE I+II and expantion packs. Pure retro!
My wife and I usually just play cooperative games against computer opponents, so one of us created a game and the other tried to join. No luck!
Then I began the troubleshooting:
- Disabling firewall
- Testing DirectPlay using dxdiag (Checked out OK)
- Analyzing log on internet router (DLink DGL-4300).
- IP Packet analyze using Ethereal.
- A lot of Google!
Nothing helped, and my temper was quickly reaching the red zone...
Finally while being at a birthday party, it dawned on me. The problem might be physical! The internet router I use only has 4 Lan ports, so some network devices are connected using an old noname 8 port 10/100 switch. As it happens, I was connected directly to the router, and my wife through the switch. As soon as we were connected to the same physical device it worked.
Lesson learned!
Update! Seems like a computer that has been in stand-by or hibernation can be causing similar symptoms as described above.