Network Slowness

[wardog25]

I've been trying to troubleshoot some slow users for a long time.

I have upgraded their server, which seemed to have no effect. they are on a new windows 2000 server and the usage on the server for processor/ram/and disk rarely goes over 15%. (they update database files if you are curious)

Are there utilites I can use on a windows 2000 server to figure out where the slowness is? Perhaps it is network traffic, but none of the other users are slow, only the ones on that server.

 

[BigShyBear]

I've had this happen because the customer had the server in 100Mb/s mode on CAT3 (10Mb/s) wiring. Shows up in Perfmon, add a counter for the network interface, packets received and a second counter for packets received errors, see if you are getting a large number of packet errors.
In this customers case I had to have wiring guys run new lines.
Some network cards (including Compaq) also have utilities that show in realtime the number of packets discarded because of errors.
Also, the patch cord could be bad. It's a quick trial to swap them out with new ones - (don't use old ones lying around, get new)

 

[d1onysus]

Did you try changing which switch the server was on? May be the server is on a bad port on the switch...If it's managed check the settings on that port...is it set to auto?

 

[wardog25]

i have changed the switch port, yes. And didn't see any difference. It is an unmanaged Linksys switch. The switch auto-detects everything. I've messed with the server NIC a bit and changed it from auto to 100 full and didn't see any difference.

Perfmon results were interesting though. No packets discarded and no packet errors. But packets received per second stays constantly from 2000 to 8000, averaging somewhere around 4000 packets per second.

On all my other servers, they stay between 0 and 200 packets/sec usually averaging around 80. I did see one spike up to 2000 for a minute or two, but that's it.

What would be causing such a high packet count?

 

[BigShyBear]

That sounds like something (a bad NIC in another computer probably) is broadcasting, but it SHOULD show up in all the other servers. At this point you should try to find the source address of all the traffic. Problem is that your server is on a switch. Try installing network monitor (info on how to)

http://www.comptechdoc.org/os/windows/win2k/win2knetmon.html

and see if you can determine where this traffic is coming from. If the Linksys switch has any bandwidth utilization utilities look into that too.

 

[BuckWeet]

Sounds like a worm on your network..

Get a network sniffer, load it on ther server.. find out where that traffic is coming from, and you'll find your culprit.


BuckWeet

 

[Tezzie]

Download a copy of qcheck and run it all over the system (assuming its smallish).

It works by zapping a known file size to various endpoints on the system, look to get around 90% on a good system with a good switch, around 50% is as good as it gets if you have a old fashioned hub.

I have identified many network problems with it - and it also proved many times that the server was fast at getting the data and the fault was with the switch.

Have you got a switch that supports full duplex? not all do



Tez

 

[rpiver]

Just some real basics here which I'm sure that you've tried already.

Is it all users on that server or just a couple?

On the users computers set the NIC speed and duplex manually.

What OS are the users that are experiencing the problem running?

Upgrade the NIC drivers on the workstation and server.

Rad Piver

http://www.globalstrata.com