any network desktop works in "slow motion" for a spell

[screaminniemann]

We have a windows nt 4.0 system with only a PDC, Proxy Server internet service, and all windows 98SE clients.
All NIC cards are 100Mbps. Appearing randomly is a client
PC going into slow-motion (for lack of a better term). We have 26 users and about 4 pc's do this about twice a day. When computer is affected, the resource meter doesn't drop at all. If you wait a couple of minutes it usually clears up. Or I have to do a power off reboot to clear. If network cable is removed from pc it doesn't occur. All cable is CAT5 and I tried replacing hubs with new auto switches. Next step? What other info do you need.

 

[pbxman]

It almost sounds like packet-collisions are occurring. Are you using only TCP/IP as your protocol, or a combination of protocols?

 

[screaminniemann]

We are only using tcp/ip. The collision lights on the switches blink infrequently anyway so how do you confirm?
I have 2 24 port switches at the server room that are full,
and one hub that sends a bnc connection to another building.
at that location, (about 400feet away) is another 8 port
hub with 6 clients attached. The problem occurs on one pc
in that building, and three pc's that are straight off the
server room switches. I've tried new NIC cards and moving the pc's to different offices to no avail. Comment?

 

[french01]

Is the PC on the end of the Coax sharing resourses? Shared application, file replication, scheduled db update, mail exchange, ... anything that would be common to the 3 attached to the switch?

Just thinking a single problem machine at one end of a 2Mbps pipe and 3 hooked in at 100Mbps.

Can you swap out the problem machine with an unaffected one from the main building for a few days? Run all 4 on the main switch for a while and see what happens.

Just a thought.

 

[lorenm]

It's kinda tough to tell from your description all the details of the network. Sounds definitely like some sort of collision is occuring. How long has the problem been occuring? Is it a recent development or did you just put the network together? If it's a recent occurance than it's not likely a network architecture problem unless you recently made changes to the physical network structure. If it's just started cropping up lately, I would start backtracking changes made on the machines... new application(s) etc. NIC cards have been known to (occasionally) go bad and when they do they can do strange things...

Here's a lil refresher on network design issues to avoid collisions. If your network is within these parameters, you're not likely to have collisions happening on a 100 mbps network.

Inside a single collision domain, the following configuration rules apply: There cannot be more than five cable segments and four repeaters between any two stations in a collision domain. Only three of these segments can be multistation segments. The last two segments must connect only a station to a hub or a hub to a hub.

Hope this helps. Good luck!
-LJ

 

[screaminniemann]

Answering french01, if db updating and/or sharing of a application is a possible culpret, what would be the solution? The one affected coax end pc was swapped out to no avail and that pc still has the same problem when setup at the servers local. This pc was reformatted, flashed, and loaded up again and still has the problem. The other five pc's are unaffected and use all the same software apps. This five is going to become 20 pc's real soon.

 

[screaminniemann]

to lorenm, thanks for the help. The problem isn't new and occurs often for a week, then doesn't for a couple weeks.
The PDC is about to be replaced with a new Dell Poweredge and I'm going to win2000 for it. Who has a collusion monitoring software?

 

[french01]

Screamin', I was thinking bandwidth bottlenecks between your buildings, but you have eliminated that possibility.

You mention an Internet connection, could there be a traffic bust going outbound, an auto software upgrade happening in the background perhaps, say anti-virus definition files being updated, windows update active or similar.

You could setup Network Monitor on the PDC (installed by default) to start a capture of your traffic.

Do a benchmark of regular traffic so you have an idea of what's normal, then leave it ready to go and start a capture when the issue is live. If this shows gross increase in traffic loads or unusual traffic patterns, you will be able to identiy what is going where from examining the packets.

If the capture suggests no extra-ordinary traffic movements then perhaps we are all on the wrong track and we should be looking back at the hardware.

Sorry can't be of more help.

 

[screaminniemann]

I'll go try that right now. thanx french01

 

[hchman]

Is it possible that there is a terminator missing?

 

[MarcS1]

Have you tried changing the NIC's card setting from Auto (For speed & Duplex) to a manual setting. I have seen similar problems when for some strange reason the network cards decide to try to re-determine these settings.

 

[screaminniemann]

french01 Network Monitor doesn't show any reaction to the slowdown.
There are not any terminators missing (I assume you mean hchman, the bnc connector end cap.)
Marcs1, where would I find auto/manual settings for the NIC
card? The device manager doesn't show any. As of today,
2 pc's are showing problem. Both are connected straight off
the server's auto-switch. One with Win2000pro and the other
with win98se. Both are 100Mbs cards.

 

[screaminniemann]

french01... Network Monitor doesn't show any reaction to the slowdown.
There are not any terminators missing (I assume you mean hchman, the bnc connector end cap.)
Marcs1, where would I find auto/manual settings for the NIC
card? The device manager doesn't show any. As of today,
2 pc's are showing problem. Both are connected straight off
the server's auto-switch. One with Win2000pro and the other
with win98se. Both are 100Mbs cards.

 

[DeanSpencer]

I can help with the NIC speed setting. In win98 goto network properties, go to NIC and click on properties. Most NIC's have an Advanced tab. On this tab you can usually select the network type and speed. In 2KPro, almost the same place, properties of the lan connection, click on configure under the NIC. Should be on the advanced tab also.
Have you changed the NIC in the server? I would try that also.
Good luck. A+ MCP
deans@bellsouth.net

 

[SimonDavis]

Can I point a finger elsewhere? I didn't see any mention of what other software the PC's are using, but there are causes other than the network that could do this.

I found a big problem on my network a few years back was being caused by MS Office. Outlook was set (by default) to write everything to it's journal. This would almost completely lock the P.C's each time a user opened or closed an MS Office app. Removing the jouranl settings on Outlook solved it.

What else is running on the stations?

 

[Guest_imported]

what kind of ant-virus protectant are you using. If it is norton check in the properties that it is set to only scan for downloaded packets, and not everything that is run through the machine. I have had this happen on my network.