there are plenty of connections happening to Cirrus right now. there have been no interruptions in several weeks. the last interruption was when i moved Cirrus to new servers at our hosting provider.
the move to new servers involved a change of IP addresses. the DNS was updated weeks ago (a lookup for p2p.rtmfp.net should show 23.253.208.188 and 104.130.213.28). the old DNS names for Cirrus point at p2p.rtmfp.net, so they should still work too.
if someone baked in IP addresses in their application, then their application would have stopped working when Cirrus moved. if you have an entry in your local /etc/hosts file for Cirrus (or whatever name the application you're trying to use is itself using for Cirrus), and you didn't update your local file, then you won't reach the new servers.
i was able to connect to Cirrus just fine, just now.
what happens if you go to
http://labs.adobe.com/technologies/cirrus/samples/
and click "CONNECT"?
what do you get if you go to
?