Error: SQL Server not found or Access Denied, General network errors & Timeout expired: Find the root cause with a trace?
The following error is a frequent-faced issue by any SQL Server user :
SQL Server is unavailable or does not exist
or
SQL Server does not exist or access denied
In this regard we have already relevant post PotentialCauses_Resolution here, but still I see that as a FAQ forum/newsgroup question and the key to solve this issue is a network packet trace. This is a further digout on your analysis technique to resolve any issue, you need to be aware about network concepts where you have to have understanding the problematic issues and to capture a network trace.
You may be aware that Netmon3 (Network Monitor) tool has further flexibility to offer with the built-in ability to capture rolling traces. Over a period of time I have learned/built following technique to use this tool for further analysis. These are the steps below in order to configure Network Monitor:
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Foremost task is to download Netmon3 tool from MS-Downloads site.
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Next is to install the downloaded tool on your client machine & Server where you are getting the above mentioned error. Just additional notes on installation is by default install to <%ProgramFiles%\Microsoft Network Monitor 3>
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Then run the commands in Command Prompt (Run as Administrator) to start Netmon3.1: cd /d %ProgramFiles%\Microsoft Network Monitor 3/nmcap.exe /Network * /Capture /File %SystemDrive%\%ComputerName%_Repro.cap:100M /DisableConversations
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Few times I have seen the security policies within an Enterprise for not to install any software, in this case you can still install it on another server (such as your monitoring server) that can be used as hub as the server or to the admin port of the switch that the server is on. If you go this route you must synchronize the time between the client, server, and this third machine.
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How to synchronize is,
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If you have Windows 2003 server then ensure to switch off the TCP chimney by using another commnad prompt as:
- Netsh int ip set chimney DISABLED
- Now you need to use Netmon3 tool as command line utility to start the trace as follows (source:Techned documentation):
- [Netmon 3 installation folder]\NMCap /network * /capture /file test.chn:100M (creates 100 MB chained files)
- The CHN extension is required to chain the captured traces and also ensure to create the target folder where you are storing the trace files.
- Further I recommend this Automate-Netmon3 trace procedure blog for your reference.
- Final step of the procedure is to stop the trace by using Ctrl+C on the command line window where you started the trace.
This will give you base information of why the error is generated and obvious lead to give more information to your network administrator. If you have support contract with Microsoft CSS then you may be aware that it provides different support services which have different service levels and support boundaries and not to mention your own debugging is out of their support boundary. A support call to our product service team is needed for the debugging service. So, if debugging is needed for this issue in the future such as server service hang, I'd like to recommend that you contact Microsoft Customer Support Service (CSS) for assistance.