Techniques are disclosed for virtualizing internet protocol (IP) addresses in terminal server sessions. A client component comprises a layer service provider (LSP) and a name service provider (NSP) that intercept a socket call to associate a port with a socket for a terminal server session. The client component queries a server component for a virtual IP address, and the server component determines whether the terminal server session can use a virtual IP address. Where the session can use a virtual IP address, the server returns a virtual IP address and the client component binds the socket call to the virtual IP address. Where the session cannot use a virtual IP address, the server returns an indication of that, and the client component acts as a proxy for that socket call and any future calls for that socket.