Windows 2K3 disappears from network every sixth hour

July 21, 2012 at 00:54:01
Specs: Windows 2003
Hi all,

I have a problem here in production environment. We are using W2K3 SP2 and SQL 2008 combination. It is found that the server gets disconnected from the network every sixth hour from its previous disconnection. The SQL resources are running fine but the server itself becomes not reachable. When I mean server, its IP address, DNS name etc.

While closely monitoring the issue, we found even the RDP connection to it expires exactly at the same time. It is just an interruption of 10-30 secs and after it everything is normal. Only clue is, it exactly happens every sixth hour. we also found its happening to all the server in the VLAN at the same time.

Sixth hour i mean is, this is the pattern.. for eg it happes at 9:15 am then it will happen around 3:16 pm and then 9:17 pm and than again next day 3:18 am, 9:19 am, 3:20 pm, 9:21 pm etc. So its not exactly every six hours, it every sixth hour from its previous disconnection. The timing is keep moving.


DHCP is not enabled on the server. Its configured to use static ip address. Server is cluster based. No DHCP server in the environment.
DHCP client is running on the machine to register DNS with the DNS server. No windows firewall enabled.

So its more like a configuration issue that is something configured to do something every sixth hour from its previous instance.

Please let me know if you suspect any.


See More: Windows 2K3 disappears from network every sixth hour

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July 21, 2012 at 04:27:38
When any server connected to that vlan switch gets disconnected in the same period of time, it's most likely the switch, you have to look for.

Have you ckecked the configuration, the logs of the switch aso.?
Any hints in there?

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July 21, 2012 at 04:41:02
Network guys has looked into all their logs... No luck so far.. Do you suspect any of its configuration to be six hours ?

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July 21, 2012 at 05:05:40

Does this always happen at the same time, arround 9:20 am and 3:20 pm?
What's about 10:20 pm?

Maybe there is something in your company, e.g. shift changeover, that aways happens at this time and causes the disconnection.
Something like electric pump, or motor, that gets switched on and off at that time and interfere with the network switch, depending on, where the cabling is placed.

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Related Solutions

July 21, 2012 at 06:20:50
I gave the pattern already, its not every six hour. Its every sixth hour from previous instance. Thanks for your time on this.

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July 21, 2012 at 10:35:01
My fault. I meant 9:20 pm.

Anyway, could it have to do with shift changeover in your company?

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July 23, 2012 at 12:57:27
Since it happens on all servers that are on that vlan it points not to servers or configurations but to the switches involved in this vlan.

How many switches involved in this vlan?
How are they connected to each other?
Spanning tree protocol enabled?

Answers are only as good as the information you provide.
How to properly post a question:
Sorry no tech support via PM's

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July 23, 2012 at 14:01:45
It's worth asking make/model of the switches too.

It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.

***William Henley***

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