Windows for Workgroups 3.11 had their Netbios network protocol support + drivers but you needed additional packages for TCP/IP. At that point most of the games used IPX protocol so you needed another DOS network stack like Novell's for gaming. If my memory serves my right, Duke Nukem 3D had Netbios support but all the other games (Doom, Descent, Warcraft 2 etc) used IPX.