sorry for bumping a 5 year old thread, but how, may I ask?

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Both computers run XP Home SP2. On both computers, In the Windows Firewall, I've set the ports 10052, 10053, 10054 both TCP and UDP with hostcomputer 'zolderpc' (which is the ICS Client pc). still, I can't get neither non-pinging hosting nor not-timing out joining to work on the client. Downloading levels and tilesets from servers works fine, though. Any solution? I also tried to disable Wndows Firewall completely, but that had no luck.