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I have over 20 1200 series PoE Aironets in a large building, using multiple vlans + WPA.

Starting about 6 weeks ago, random waps will just stop responding to ping, ssh, http, and stops serving clients--I have connected via serial, and I dont get anything... Once I powercyle though, it works fine for an inderterminate amount of time, at which case it goes back to not responding.

I have switch PoE ports on the PoE switch, switched out to using PoE injecters, used a different switch, etc.

Software versions:

System Software Filename: c1200-k9w7-tar.123-8.JA
System Software Version: 12.3(8)JA
Bootloader Version: 12.2(8)JA

I also did some sniffing on this vlan (mgmt vlan) which all it currently has is the 20-odd aironets, and about 5 switches. I am seeing a bit of stp traffic, maybe a couple stp packets / second, with the current root bridge cost of 8.

I dont have any other ideas on what is going on....

Any ideas?

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up vote 1 down vote accepted

This ended up being a bug in the firmware... Found it in a memory dump of one of the Aironets, and then finally found reference to it buried in a Cisco doc. Upgraded with a fix, and they have been stable ever since.

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Two thoughts come to mind:

  1. Heat: About 2/3rds of the time I have random shutdowns and lock ups of IT gear, it ended up be caused by overheating. I've not had that with the Cisco 1200s, but I have had it with switches, routers, and servers.
  2. Cable: The Cabling: The Complete Guide to Network Wiring by David Groth claims that nearly 70% of network problems are caused by poor cabling (Page 5).

If you can temporarily rig up the 1200 in some other location and it never has a problem, then you can be pretty sure it is one or the other.

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It isnt just one WAP in one location... It is about half of them in different locations, with different cables, on different switches... Which makes it pretty clear to me that it is not a systemic cable or heat issue.... – Josh Brower Nov 4 '11 at 3:02
Why couldn't it be a heat issue? If they're all the same model and there is an overheating problem, it seems to me that they'd all be affected by it, to varying degrees. Is there anything in common environmentally with the units that have experirenced the problem? – joeqwerty Nov 4 '11 at 3:11
Perhaps some condition has changed you're not aware of? Spanning tree craziness? – SpacemanSpiff Nov 4 '11 at 3:19
Spanning tree - good thing to check. Hadn't thought of that one. @SapcemenSpiff you should make that a actual answer so you get the points. – SBWorks Nov 4 '11 at 3:47
RE: Heat issues. Because a few of them are out in open air hallways, one right by my office, and I know what the temp is, and it is not enough for overheating... RE: Spanning tree - would there really be a condition where the serial connection doesnt respond? – Josh Brower Nov 4 '11 at 12:13

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