Updates to the Steam Client and the Half-Life 1: Engine have been released. The updates will be applied automatically when your Steam client is restarted. The specific changes include:

Steam Client

• Fixed client failing to login to the Steam Authentication servers on machines with multiple network interfaces

Half-Life 1: Engine

• Fixed game servers failing to connect to VAC servers on machines with multiple network interfaces

Fixed "-sport" parameter being ignored
Implemented a client cvar value querying API (to replace the alias method various 3rd party tools were using). Servers can call enginefuncs_t : : pfnQueryClientCvarValue() and will get a callback for that cvar value via NEW_DLL_FUNCTIONS : : pfnCvarValue().
Fixed RCON failing when you were not connected to the server itself