I am behind a firewall. What ports need to be opened for hlds?
Incoming UDP to local destination 27015.
Outgoing UDP to remote destination 27010, 27012.
Outgoing TCP to remote destination 5273.
Outgoing TCP to remote destination 7002.
you also need the following ports open:
27012 - for secure modules
27020 - for sound
Oh and make sure you open UDP ports.