I have a problem with SQL Server 2000 running on a Windows 2000 Service Pack 1 (SP1) cluster. Occasionally, I can't access the SQL Server Virtual Server by using TCP/IP. When the problem occurred the first time, the Virtual Server stopped registering SQL Server's active port 1433, although the port was in the configuration. I discovered then that if I moved the cluster group to another node, I could use TCP/IP to access the server with the port active. When the same failure occurred 2 days later, moving the cluster group back to the original node refreshed the port. I can always access the Virtual Server without a problem through named pipes. Do you have any idea what's going on?
When SQL Server failed over to the node, Win2K for some reason had already assigned port 1433 to another application. We've experienced the same behavior at Microsoft. Win2K seems to be more aggressive at giving away SQL Server's port than Windows NT was. Unfortunately, you can't do anything other than change the port number to one that's lower than 1024 so that Win2K doesn't give it away.