Coldfront's server list, with ports:
- irc.coldfront.net (random server)
-
- storm.coldfront.net port 6667 SSL port 7778 - Central USA
- ice.coldfront.net port 5556,6667 SSL port 7778 - Europe (NL)
- subzero.coldfront.net port 6667 SSL port 7778 - USA
- frozen.coldfront.net port 6667 SSL port 7778 - USA
You can also try using Coldfront's Java client, at http://www.coldfront.net/webchat/chat.php
If neither of those work, you can try Mibbit as mentioned above. If you are connecting from a public place, i.e a library, the connection could be blocked (I'm pretty sure I got Mibbit blocked in my school district, heh), or it could be a port or firewall issue.