SQL Server Performance

sysprocesses net_addess change when not on network

Discussion in 'General DBA Questions' started by Robert Mizzaro, Jan 14, 2003.

  1. Robert Mizzaro New Member

    I am running an instance of SQL Server 2000. The
    Net_Address in sysprocesses is different when I am not
    connected to a network. However, when I am connected to
    any network, Net_Address matches the Physical Address of
    the computer on which I am running the SQL Server
    instance.

    Can anyone provide an explanation of why SQL Server would
    identify an address that does not match the physical
    address of the computer running the instance.

    Also, can this be avoided? I have a program that checks
    the address that SQL Server provides.

  2. bradmcgehee New Member

    The Net_Address is the MAC address of the computer that initiated the connection to SQL Server, not the MAC address of server running a SQL Server instance.

    I am not sure what you mean by "The Net_Address in sysprocesses is different when I am not connected to a network." Can you be a little more specific.


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    Brad M. McGehee
    Webmaster
    SQL-Server-Performance.Com
  3. Robert Mizzaro New Member

    Thank you for your quick response.

    Hopefully, I can elaborate. An example, for testing purposes, I run an instance of SQL Server 2000 on my laptop. I test my application on my local instance. When connected to the network, the net_address in sysprocesses matches my physical address. However, when I disconnect my computer from the network and reboot, the net_address in sysprocesses of my local instance of SQL Server changes and does not match my laptop's physical address. In fact, I get a new number after each reboot. As soon as I place my network cable back into my NIC, net_address in sysprocesses and my physical address match.

    My question is why they would match when on ANY network, but not match when off a network. But, why would SQL Server look at an address differently because the computer is not connected any network?

    Robert Mizzaro

  4. bradmcgehee New Member

    I think I understand your question now, and the behavior you describe is strange. I would expect you to always see the same MAC address in your case because the client is always your server. My guess is that, for some reason when you are disconnected, that SQL Server is unable to identify the correct MAC address (which should be your local MAC address), but this is a guess.

    Is this feature important? Will there be cases when you need to know the MAC address of a client when it is not connected to a network? When connected to a network, I would expect that SQL Server would always be able to identify the MAC address of the client machine.


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    Brad M. McGehee
    Webmaster
    SQL-Server-Performance.Com
  5. Robert Mizzaro New Member

    It's not really important at our clients that are always on a network. However, it's causing a problem with our developers that test locally. Our product does check both addresses to make sure that they match. We do this at clients for certain security reasons.

    Robert Mizzaro
  6. bradmcgehee New Member

    I wish I could offer more, perhaps someone else well. I guess, as a last resort, you could include some logic to test for a network connection, and there isn't one, then to ignore the MAC address. You could also call Microsoft support and ask for their advice.


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    Brad M. McGehee
    Webmaster
    SQL-Server-Performance.Com

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