Streamyx has blocked port 6667 since 2012. The reasons given were ambiguous and in bad English:
This port is widely known as vulnerable and will jeopardize TM Network and TM Services if it let be open. TM has the rights to implement any blockings to any identified harmful ports to secure TM’s network.
Fast forward to 2015, and port 6667 is STILL blocked. Which means the only way to access IRC is if the port has an alternate port to connect to, use a web client or simply connect to a VPN.
This is pretty bad since many groups still hang out on IRC like coders, support groups and other interest groups and not all of them care to open an alternate port.
So if you’re unable to connect to IRC and you’re with us already, consider just connecting to BolehVPN then to IRC and you should be able to chat freely and securely.