So... My title was just too long... My question is ... What do I need to do to connect to mIRC behind a router?

I have an Cisco EPC2425 router and can't seem to find a tutorial on how and what to portforward FOR MY ROUTER to work with mIRC...

Everytime I try to connect to ANY channel/server with mIRC I receive an error like: Unable to resolve your hostname: Domain name not found. Using your IP address instead... and then I wait for hours and it keeps retrying and nothing... the same error...

Can someone give me a step-by-step tutorial on how to and what do I need to portforward/trigger/filter for my router to work with mIRC?

Thank you very much.