RAS install failure with Duplicate Name

I am stumped on a RAS install on my NT4 server, using a 56K modem. Upon completing the RAS configuration and restarting the server, the event log is full of 7001 errors – workstation service can’t start because a duplicate name exists on the network. I cant find a duplicate anything. The network wont start – no nothing in Network Neighborhood – and there is no RAS dial-up either. Please assist Thank you!