3750 PoE issue

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Jul 7th, 2008
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one of my customer site 3750 (stacking) switches suddenly stoped issueing power to Ip phones for some time and after some time it provided power to the phones . this happend in 2 floors in the same building .. Any clue regarding this issue ? IS there any known issues like this ?

If anybody faced the similar issue pls update me .

Thanks in Advance

-- Dinesh

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glen.grant Mon, 07/07/2008 - 13:45
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Sounds like a couple of the switches int he stack reloaded for some reason either power problem or a IOS bug . if it at the same time i would suspect power . The main disadvantages of running everything (phone and data) thru switches. If this is a critical issue then they should consider power backup of some type.

rescueskier Thu, 07/17/2008 - 04:49
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I am having the same issue with a stack that has a 24port PoE and a 24port Non-PoE. Both are Gig switches. Both are EMI. A reboot fixes the issue for about 2 weeks, but if somebody disconnects a phone and reconnect, no power. It won't just stop sending power to the phone, just only when it is disconnected and then reconnected. Currently running 12.2(40)SE with the IPSERVICESK9 image. I have 7960 and 7941G phones on the PoE switch.

What we are seeing is that the Master changes to the non-PoE switch and then the problems start.

What we are going to do is this. 1st, upgrade to the 12.2.(44) code. 2nd we have made the PoE switch the master via the switch X priority command. Hopefully this will stabilize the problem.

TcsHungary Thu, 08/07/2008 - 07:30
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I have only 1 3750 G , but not used with cisco IP phones .

The thing is that same thing happens if I disconnect a phone ...it will not boot up again and no power from switch.

What is this ? Is it really the IPS?


rescueskier Thu, 08/07/2008 - 12:29
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We did up grade the code to 12.2(44)SE2 and I have not had any reports of issue from the local administrator. We are in a point of our production cycle that does not allow him to test. I won't know more until late this month (August).


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