How to connect Left 4 Dead

1.  At the opening menu press ~ the console will show up
2.  Type sv_lan 1 enter
3.  Type sv_allow_lobby_connect_only 0 enter
4.  Type net_start enter
Note:  Look for the IP address you will later use this example 192.168.1.89
5. Type map space then the name of the map.

For the second player

1.  Press ~
2.  type connect then the IP address example connect 192.168.1.89