No firewalls running on the server. I connected everything directly through a switch (not a router). From the client workstation, I can ping the server and I can see port 8000. I turned off all filtering on the NIC. There should be nothing that blocks it. In fact, I set up the RIS client to contact the database by host name and the error I am getting is by IP address so netbios isn't an issue. All signs point to a certificate issue.