Master Server replies, but nothing will connect

[Lord Vader]

You should close ports if you are not running a server.

Remove the router from the mix. Test if its the router borking your connection by directly connecting to modem

change cat5 ethernet cable

restart modem

START run cmd.exe ipconfig /flushdns

I could be wrong but im feeling your router is evol

[Sonic]

tried everything.. flushdns, new cat5, restart modem (it's an xfinity modem and I want to get into its settings but i don't have the password and comcast won't give it to me)...
Also I downloaded CS 1.6 and the same problem happened even when I tried all these solutions. Strangely, Blacklight retribution servers are fine (but my graphics card isn't good enough for it).

[Skinny-Dog]

Cool, i didn't know that Courage the coward dog is called Sonic...