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dubdub's avatar
dubdub
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Jun 03, 2011

Connecting to SQLServer through a virtual server

Hi all,

 

 

I am trying to set up a virtual server for a SQLServer 2005 named instance. We don't have IP addresses associated with the named instance, only with the core database server; so this is proving a little more interesting than I had hoped for.

 

 

So I have my database on server1\instance1, which is on port 4904 in this particular case. I have a pool member set up pointing at port 4904 on server1's IP address (1.1.1.1). My virtual server is set on its own IP address (2.2.2.2) and port 4904 also.

 

 

When I open SQLServer Management Studio, I can successfully establish a connection to my database by connecting directly to "1.1.1.1,4904". However, when I try to connect using "2.2.2.2,4904", I get an error message saying "Cannot connect to 2.2.2.2,4904. Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding." Before the timeout message is returned to the client, I can see the connection in the stats for my pool member, so I know it's getting down to that point in the conversation.

 

 

Any thoughts on what I'm missing, or might need to enable to get the pool member to connect successfully?

 

 

Thanks,

 

Jen

2 Replies

  • Hi Jen,

     

     

    I'm not sure why this wouldn't work. Can you try capturing a tcpdump filtering on host 1.1.1.1 or host 2.2.2.2 to see exactly what's happening?

     

     

    tcpdump -i 0.0 -s0 -w/var/tmp/sql.dmp host 1.1.1.1 or host 2.2.2.2

     

     

    You can use Wireshark to analyze the tcpdump on an external workstation.

     

     

    Aaron
  • dubdub's avatar
    dubdub
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    Hi Aaron,

     

     

    I pulled a couple of tcpdumps and saw that the port was changing on the backend. I had missed enabling SNAT automap on my VS and also switched to a straight TCP client profile, and everything started flowing. Thanks for the help!

     

     

    Thanks,

     

    Jen