Connection issues with L4D only...

[SonicAngel]

I can't connect to any server in L4D or L4D2 right now. It seems something isn't running smoothly. I can connect to any other server in any other game (CS:S for one).

In L4D it either says "connection failed after 10 attempts" or it manages to connect, at which point I see the game stuck and it has small bursts of connection where all the sudden I see where everyone is, but then it gets stuck again for 5 sec and then I see where everyone is again and so on.

Any idea what is causing this?

I tried verifying game files but since this happens in L4D 1 as well I doubt it's that... I also tried restarting everything (PC, router, modem).

Running Win 7 64bit
Core2Quad 9550
Radeon 4890 Vapor-X
4GB OCZ Platinum 1066MHz

[Donrenegade]

Same problem here, but for me the problem is for all source engine powered games... All other games have no problems when playing online

[SonicAngel]

Where are you from? I have a sneaky suspicion the fault lies with my ISP...

[SonicAngel]

Ok then... It seems the problem is my router (tplink tl-wr841N). I connected my PC directly and it works like a charm, I used a port checker and it seems my router isn't forwarding Steam ports even though I set it all up properly...

Why this changed since last night when all was working well I have no idea...