I presume by your ability to post that you are able to browse the web without problems? If so, it is unlikely to be your ISP's DNS server (the one acting as your local nameserver) at fault as it is responsible for the resolution of all hostnames, webservers, IRC servers, etc.
I cannot resolve irc.dynastynet.net from my home machine, nor from a remote shell on one of the machines at uni. Connections to dynastynet.net's DNS servers are timing out which would seem to indicate that the problem is theirs and the poor bastard who's the on-call sysadmin on Christmas day has probably had his cellphone ringing like crazy (in our company I am that poor bastard, thankfully nothing has (nor will
) happen).
Are you able to connect to other IRC servers like say...pacific.nsw.au.austnet.org ? This is one I know is up (at least at the time of posting), obviously it's on a different network, but it'll at least tell you if your settings are allowing IRC connections out of your machine and into the Internet.