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Active flag on the TCP/IP Properties page of SQL Server Configuration Manager

I’ve been unable to connect to a server via one of its aliases for about a week.  When I looked at the TCP/IP Properties for the instance I saw the following:

Note that the Active flag for IP1 is “No”. BOL defines the Active flag as “Indicates that the IP address is active on the computer.” However I know that the IP is active since it is working for another instance on the same server.
I tried changing the Active flag to “Yes”, then applying the changes. When I brought back up the page it still showed “No”. Next I restarted the instance, no change. Then I restarted the server, still no luck.
Eventually I checked the registry. They key for IP1 is: [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10.SQL2008\MSSQLServer\SuperSocketNetLib\Tcp\IP1]
(The part MSSQL10.SQL2008 represents the instance. Change it to match the instance you are checking.)

Under this key is an entry “Active” that is 0×00000001 (1) for “Yes” and 0×00000000 (0) for “No”. I first changed the flag from 0 to 1. When I went back to SSCM the TCP/IP Properties page now showed:

Once I restarted the instance I could connect normally!

I’m a little surprised that SQL doesn’t update this flag without a registry change and I wouldn’t recommend it normally, but in this case it seems necessary.


My name is Kenneth Fisher and I am Senior DBA for a large (multi-national) insurance company. I have been working with databases for over 20 years starting with Clarion and Foxpro. I’ve been working with SQL Server for 12 years but have only really started “studying” the subject for the last 3. I don’t have any real "specialities" but I enjoy trouble shooting and teaching. Thus far I’ve earned by MCITP Database Administrator 2008, MCTS Database Administrator 2005, and MCTS Database Developer 2008. I’m currently studying for my MCITP Database Developer 2008 and should start in on the 2012 exams next year. My blog is at www.sqlstudies.com.


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