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Detecting Network Issue - Help



Im new to this network analyzing and am trying to understand it more. I have a network issue on the company network that im trying to troubleshoot without much luck at the moment. Im hoping someone on here may be able to point me in the right direction so I can find the cause.

The issue we have is as soon as a network device is turned on it causes network timeouts (tested using "ping" to multiple devices, get timeouts to all devices pinged except switches). It can be a PC or Printer. As im sure you can imagine this causes big problems, the network may only drop for one second but its enough to cause problems. This becomes a nightmare when people come in and start their PC's in the morning.

I can easily replicate the problem by simply turning a device off then back on so that should make the troubleshooting easier, I just need to know what to look for and what to ignor.

Any help would be greatly appreciated.

Thanks Dan

asked 20 Sep '10, 04:44

xiztrn's gravatar image

accept rate: 0%

One Answer:


So only your switch remains up, while all active devices on it's connected ports drop off? I would take a very serious look at that switch. Spanning Tree problems? Someone looped back a switch port to another?

answered 20 Sep '10, 08:40

Jaap's gravatar image

Jaap ♦
accept rate: 14%

I agree with xiztrn. I would also take a hard look at the hardware itself. You could easily have a corrupt flash or the switch may simply be dying. Can you provide details on make model and OS?

(06 Oct '10, 07:25) blacknight

Please provide more detail regarding the device and how it's connected to upstream network devices (switch, routers, firewall, etc). Spanning Tree can be confusing and difficult to diagnose. Also check out VTP, if it's in use, to see if the new switch is trying to push a conflicting vlan database.

(12 Oct '10, 06:24) GeonJay