NAT CheckVersion 3, with UDP and TCP support Check Your Network Address Translator for Compatibility with Peer-to-Peer Protocols NAT Check by Bryan Ford, web magic by Dave Andersen Hosted by the MIDCOM-P2P project on SourceForge This page, the NAT servers, and the results database are no longer being actively maintained. (Sorry, just no time; I have to focus on other projects now!) For a detailed overview
