IRC - I can't access one particular server (yet others are fine...)

Hi. Yesterday, I used IRC for the first time and I've hit a problem – it seems I can access any server except the one I actually want which is irchighway.net.


I've tried two IRC clients – mIRC and adiIRC – and the story is the same: trying to access irchighway.net gives me the error “unable to resolve server”. At first, I suspected interference from my firewall or antivirus but the fact that I've successfully downloaded an ebook from undernet.org suggests I don't have a connection issue. By way of further testing, I have:
disabled my firewall
disabled my AV, and

on my router, opened the specific ports that irchighway uses.

All to no avail. I'm at a loss to understand how I can't access just this one server. Can anyone tell me the cause (and cure) of this? Thank you.

Thanks, Ken. I knew of that page, it's where I got the port numbers from. The two clients I was using have dropdown boxes for the server so I was always using the correct address.

Problem solved, though - my DNS settings were those of OpenDNS which, for some reason, blocks irchighway. I changed my DNS numbers and all is now well.