I have a weird issue. I have 4 or 5 switches (all different makes) and intermittently they drop all network traffic. They don't lose power but just drop all traffic. They don't even do it at the same time. There is no consistency. Any ideas would be greatly appreciated!
Thanks
You have to provide a LOT more info before any here can help you.
Everything ends up plugged into a 4506. You have 4 other swithces (other than the 4506). Two are directly connected to the 4506 and the the last two are plugged into the 2 that are directly connected to the core switch. So there is some stacking.
VLANS are setup but disabled. Not sure exactly whey someone did that though.
No trunking.
Switch models are: 4506 and 4 3550 switches.
Problem has no consistency so I can't give you when it occurs. It lasts only for a few minutes.
Thanks
Thats what I was thinking. But my question is why now? they have been operating fine for quite a while.
So if there is no trunking and no VLANs, that implies that you have one flat network all sittting in the same IP subnet . Is that correct ?
What IOS version is running on the 4506 and the 3550's ?
Is spanning-tree enabled on all of the switches ?
Please post "show cdp nei detail" from each of the 5 switches
Do you have internal syslogging enabled? If not configure
conf t logging buffer 10000 debug no logging console exit wri mem
The next time problem occurs, check the logging buffer using "show log" command
Hi Daniel,
Assuming it really is a FLAT LAN (based on no trunking or VLAN's), then I wonder if you are running into a Spanning-tree issue. Have extra hosts been sowly added to the network recently? Are you sure no-one is adding another switch below the "known" switches?
Also your original post states -
and yet above you say - "> Switch models are: 4506 and 4 3550 switches" I assume you meant they are all different MODEL's, not makes?
This could be a spanning-trree or MAC-table type issue.
Cheers.............pk.
I have seen issues where a faulty NIC card causes enough chaos in the network to stop all traffic for a few minutes due to a flood of bad traffic.
Have you added any new hosts to the network recently? How often does this happen? Once a month, every 5 minutes? The similar issue that I spoke of would happen a couple of times per hour.
Do you graph you switches? If not, try using the folloding commands to find any abnormality: show int summary show int | in packets/sec show int | in errors
Happy hunting!
-Wil
Daniel wrote:
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