Bizarre CPU Usage Spikes

**Linthade** · December 14th, 2004, 01:57 PM

Got hit with a new one today, haven't resolved it yet so thought I'd ask if anyone had any ideas.

Have a computer that has an onboard 10/100 nic. When it is plugged into the network at their building, every 1.5 seconds a 61% CPU utilization spike occurs, causing the mouse and everything else to lock up.

If you take the patch cord off, the CPU spikes quit. So, my first thought is bad network card right?

I take the machine to my shop and plug it in on my network, which is configured similarly to the customer's. No problems, no cpu spikes, nothing. Perfect operation.

I have replaced patch cords, different ports on the switch, different ports on a patch panel. All same result at the customer location. Bring it to my office, and it works just peachy. My thought at this point is to disable the onboard card and put in a secondary card and see what happens. I'm not sure about this because the onboard works just fine at my place.

Ideas?

*lin*

**Drone2903** · December 14th, 2004, 03:58 PM

Looks more to me like someone is either broadcasting (255.255.255.0) or u have some sort of attack going on either on that machine or on your customer's network. Is this the only pc with those cpu spikes? I'll bet not.

**Linthade** · December 14th, 2004, 04:24 PM

Originally Posted by Drone2903

Looks more to me like someone is either broadcasting (255.255.255.0) or u have some sort of attack going on either on that machine or on your customer's network. Is this the only pc with those cpu spikes? I'll bet not.

Yes, that user is the only one reporting a problem. I have attached my laptop to that same link and had no issue.

*lin*