I have three SQL Server 2008 instances running on a cluster. SQLInstance1 is listening on default port 1433, SQLInstance2 is listening on port 39999 and SQLInstance3 is listening on port 49999. Can SQLInstance2 listen on port 39999 and 49999 when SQLInstance2 and SQLInstance3 are running on the same node of the Windows2008 cluster?
1 Answer
The answer is no. On the same server or on a node of a cluster, you cannot have two instances of SQL listen on the same port number. The first instance that starts up will bind to that port number, and once the other instance tries to start up with the same port number it will receive an 'bind to port' or 'tcp port already in use' error.