Use the latest TCP/IP stack from Microsoft if you use Windows for Workgroups. The early TCP/IP stacks had lots of bugs.

Microsoft has released an incremental upgrade to its TCP/IP 32-bit VxD drivers. The latest release can be found at ftp.microsoft.com, located in /Softlib/MSLFILES/TCP32B.EXE. There is an update.txt file there that describes the problems that were fixed. New files include WINSOCK.DLL, TELNET.EXE, WSOCK.386, VNBT.386, WSTCP.386, TRACERT.EXE, NETSTAT.EXE, and NBTSTAT.EXE.

More information about this patch is available in Knowledge Base article 99891.