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Network issues after NIC reinstall

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jadixon

Programmer
May 22, 2008
33
US
I am not sure if this is the correct location for this or not.

This is a bit of a long-winded story. I started out having issues connecting through a VPN using RDC to my computer at my office from the computer at my client's site. I determined it was specific to the computer at mu client's site, and that it had to do something with the NIC. So after doing some research, I stumbled on the solution of uninstalling then reinstalling the card (through the device manager). After a reboot, the RDC worked. I thought all was well.

That was until I now try to open different software that accesses data on the network. Windows Explorer is ok, but opening Outlook takes a long time. The real problem is with SQL Server. It takes FOREVER to open, and then when I click on anything, it takes a long time to perform its task. None of this was at all slow before - response was immediate.

Does anyone know what setting may have been corrupted when I reinstalled the NIC? This is making me crazy! I can't get any real work done.
 
This can be caused by a couple of things, what springs to mind at the moment is an incompatability between what the switch and NIC things are the correct settings.

I have seen in the past NICs that are set to auto-negotiate don't use the same settings that the switch expects (this goes back to 3com\Cisco) you may have to find out what the switch is defaulting to (for instance 100\Full or 1000\Full) and set the NIC to the same settings.

Also have a look in the eventlog to see if there are any hardware issues, you never know if you have a card that's reporting issues (called a jabbering card) and it may be worth while setting up monitoring on the pc to see what traffic is going over the link. You may want to see if there are multiple protocols installed on the PC, whether the PC has the correct DNS entries as well, even better you could also try reregistering the PC back into DNS (assuming it's an XP machine you could do an ipconfig /registerdns).

Have a try and see what happens.

SimonD.

The real world is not about exam scores, it's about ability.

 
I looked in the event log, but there were no hardware entries. However, I found that I am getting DCOM errors trying to communicate with the sql server I am accessing.

I will now redirect my efforts into tying to correct my DCOM issues. Thanks for the advice.
 
I have not found a solution, but a work-around is to log into SSMS with the IP address instead of the name. It works just as fast now as it used to. I still get the DCOM errors, but at least I can work again.
 
After realizing the DNS name was the problem, I went into the hosts file (in the windows\system32\drivers\etc directory) and added the ip address and name of the system I was trying to connect to with SQL Server. Now that it is in the hosts file, the system is fast again and no more DCOM errors!
 
Lots of VPNs don't handle split DNS very well, especially if they are using selective networking. It might be trying to query THROUGH the VPN for a DNS server or perhaps it is trying to bring the VPN up to query a DNS server.

One could use profiles to disable/enable (I am not sure that one can disable on the fly). the VPN driver to verify or use wireshark to see what DNS server you are trying to use. (if the VPN is up, you only will see packets to the VPN destination, likely encrypted).

Reloading the NIC sometimes reorders how the TCP drivers are sorted, which doesn't always work.

 
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