LM-NT-OS/2 Connections

Do the client and server reside on different subnets but connect via NetBIOS-over-NetBEUI?

If they do, the client cannot connect to the server because this protocol setup only works within the subnet. You must have NetBIOS-over-TCP/IP to connect a client and server on different subnets. NetBIOS-over-NetBEUI does not route.

Does the client attempt to access a service using NetBIOS-over-TCP/IP on the other side of the router?

In order for a client to find a NetBIOS name on the other side of a router, it must have the ability to map an IP address to that NetBIOS name. You can accomplish this by using static tables, Windows Internet Naming Service (WINS), or Enterprise Name Server (ENS) to configure the client to resolve the service name to its associated IP address.

Does the client use the same SMB dialect as the server?

Some older client software does not use the extended SMB protocol in the same way as the server. To force the client to revert to the core protocol, use this command:

tnservice -M -r NB -s servicename -a smb-protocol-level=on