Link UP - Link Down in log

Unanswered Question
Apr 6th, 2007

Hello all.

I have a WS-C2924-XL, and have noticed a lot of up / down on port 17. I this normal behavior or something else I should be concerned about?

Attached are the log and config.



I have this problem too.
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sundar.palaniappan Fri, 04/06/2007 - 10:34


Link up/down status is normal. However, f0/17 seems to be flapping a lot. Check the device connected to it, cable or even a faulty switchport can cause this behavior.

Do you see any errors on int f0/17?



stevebybee Fri, 04/06/2007 - 10:52

Its my computer that is connected to f0/17, and the NIC is built in. Its an Intel Pro 1000. I have disabled the power management in windows.

The cabling is Cat5E shielded and I would estimate the run is 30ft. The cabling was all run and terminated by me. Tested with a fluke LinkRunner(wish it was mine :P), and tested fine.

sundar.palaniappan Fri, 04/06/2007 - 10:59

Try setting the speed and duplex to auto on both the switch and the PC NIC and see if it helps.

Can your computer successfully connect to the network?



situwayne Fri, 04/06/2007 - 11:10

this looks normal based on your log.txt

noticed the pattern of the up/down.....down...up...down...up. this maybe the normal behavior for this host. it's only happen 3 times in 3 days.

if you get 10 or more up/down in a minute, that's what I call link flap. chk the switchport for errors. I would expect you see a few errors. clear the counters and check for error in a day or two. as long as the interface shows pretty clean, then there is nothing to worry.

narutouzumaki Tue, 04/10/2007 - 06:17

I have a too that problem, but it started a while ago, on all switches (40-2950+2960) some interfaces are going down & up for 2 seconds, when they are on switchport portfast the line protocol just go down & up, without goes the link too for 3 seconds. I dont know what it is this doing. Its too often to be normal


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