I too had this problem and tripped across another thread with the posted port numbers in use for c2
From: Demo Readme | #000
Game Port Usage
For all traffic between server and client 'game' port is used
(default 64100 - net_lobby_gamespy_online_port).
Ports
SDK Service Hostname Type Local Remote
Available hbmaster3 crysis2.available.gamespy.com UDP Any 27900
NN natserver1 natneg1.gamespy.com UDP game 27901
NN natserver2 natneg2.gamespy.com UDP game 27901
NN nat neg Game client UDP game game*(other game)
QR2 hbmaster3 crysis2.master.gamespy.com UDP game 27900
QR2 Incoming queries Game client UDP game Any
CDKey keymaster key.gamespy.com UDP game 29910
SAKE Profile settings/stats crysis2.sake.gamespy.com TCP Any Any (def:80)
Chat Any IRC server peerchat.gamespy.com TCP Any 6667
GP gpmanager gpcm.gamespy.com TCP Any 29900
GP searchmanager gpsp.gamespy.com TCP Any 29901
SB gmaster3 crysis2.ms5.gamespy.com TCP Any 28910
SB Server queries game servers UDP Any game*(target server)
RSS RSS Feed lb.crysis2.ea.com TCP 80 80
Default value for 'game' is 64100 (can be adjusted).
For incoming UDP traffic, only port "game" ( default 64100)
is required to be opened.
I am using Mcafee Virusscan Enterprise which, by default, blocks the IRC port 6667. I added an exception to the access protection rule for crysis2.exe and now I am able to connect. So check your virus protection and firewalls as this was not initially obvious to me. At least a portion of the authentication process runs across port 6667 so university students should check with your network administrators to see if this port has been blocked - my guess is that it is.
Seems like they are using alot of the same port number that Tribes used to use ..... maybe they can put a jetpack on that nanosuit