Glitch causing quick interrupt of network?

Okay, I have a weird one. Quick background - im the IT Admin at a company that has about 100 users. We recently upgraded our entire IS. We have one Server 2008 with Exchange 2007 as our DC and another Server 2008 R2 server that acts as our backup DC and Trend Micro Proxy (among other things).

We currently use an Access database (2007) and have not had any problems until recently. We are slowly deploying Windows 7 in the envirnment and overall we have had very little problems and it has gone very smoothly. However, there is one nagging problem that I cannot figure out.

At random points in time I will have employees working in Access (the main database is stored in a central location on the server and the client only sees the forms side) on the forms and will get a message that states that access has lost connection to the network and the table is filled with null values. The user then can immediately close and reopen the forms and all the data is back again. While the data is safe, this is an annoyance and makes the powers that be uneasy.

Here is the thing - this did not start happeneing until I moved them to Windows 7. All three of these employees are getting this issue, at random, about 1 time a day and they are all the first three that moved to Windows 7. I initially thought it could be Trend Micro IWSS proxy, but it cannot be for two reasons - 1.) it is LAN traffic which does not involve TM, and 2.) It does not happen to anyone that is using XP still.

There are no error logs and so it seems that just for a second the network connection blips. Any possible reason why? On a side note, all three computers are dell dimensions of different varieties and I only used the Windows 7 supplied NIC driver. Could this be an issue with needing to install the actual manufacturer NIC driver or do you think this may have something to do with an IPv6 issue? (I read somwhere that disabling the IPv6 could help a problem like this, but I am skeptical. Thanks.

Mike

I would start by looking for a newer driver from the manufacturer. Often times Win 7 uses a generic driver that may or may not have full functionality. Drivers have been coming out daily on some manufacture sites so I would look into that if I was you.

Okay, I still have not solved this problem, but I do have more clues!

So we have deduced that it is happening at the exact same times every day. There are two that it happens to the most and one goes down at exactly 4:55 PM every day, and then 9 minutes later the other goes down as well.

So I am thinking that it must be some sort of update or other service that starts at that time. Not sure what it is though.

So my question is - knowing that this happens around the same time every day how can I investigate further to see what may be triggering this?

By the way, not sure if I mentioned this earlier or not, but there is not one thing in the error logs regarding this error.

Thanks!

Mike

It sounds like the router is having problems with DHCP lease renewal process, the usual lease renew is at 12 hours on most routers, if that doesn't happen then it will cut off at the 24 hour mark, it's a fairly common problem from what I have read.

The usual fix is just to install newer firmware if you want to keep using DHCP IP assignments, or setting static IP's on each machine should also fix the problem.

People with this problem reported that using static IP's fixed it.
Quote below:
Today it DIDNT Disconnect
So if you want your computers to keep running without disconnect
Set static ip on each machine and the problems gone..

And leave the router to have DHCP if someone comes around and connects.
And to be sure, Reserve all IP you have set to static (manually) so the DHCP
dosent try to give out the one you have set to static.

That is a great idea and I hadn't even thought of that. I will (reservedly) give it a try! I say that because Im always hesistant to get too excited about such easy fixes! Thanks and I will report back any improvements and issues.

Mike

Sounds good shelzmike, there were reports about this type of problem all over the internet and the fixes all seemed to be similar with only a few options to choose from.

No go..I supplied a static IP on the PC itself and assigned a reserved IP on the DHCP (Server 2008) server as well and it still happend like clockwork. I am still thinking it may be something related to an update service or something that starts running at that time. Is there anyway to do an audit to see what is happening at that time?

Like I said, the logs say nothing about anything except that the Access program shutdown and it was unexpected...duh..

Mike

Did you try the firmware update yet? There are so many cases here where a firmware update fixed problems I have lost track, also many compatiblity problems with older routers refusing to work correctly with Windows 7. I'm not sure what model router you have but it's worth looking into I'd say.

Let me ask you this though. I believe what you are saying in most cases; however, how would a firmware update on my router help - our server handles the DHCP role - our gateway has nothing to do with it.

Mike

I'm just saying that the problem seems to be directly related to the Win 7 upgrade machines so a compatiblity problem seems most likely. Perhaps your server needs to change settings to handle the DHCP assignments properly on the Win 7 machines. The fact that your connection shuts down at the same time everyday also points to a DHCP lease expiration problem of some sort. Which server are you using, perhaps there is an update for it to work with Windows 7...