AIR-LAP1242AG-E-K9 shutting radio interface (WLC 5508)

[E07837_2]

I am wondering if anyone has seen this before. We have about 50 AIR-LAP1242AG-E-K9 access points connected to a WLC5508 running 7.4.100.0. These were all being used as autonomous APs previously and were converted when the controller was installed. About 12 of these have a lovely feature where their radio interface goes down at random. The radio is still in enable mode but the opertational status is DOWN. It seems to happen particularly when there has been a power outage and the AP rejoins the controller. All of the other 1242s are fine and never sees this problem. The APs are all on power injectors.

Once the radio is down, the only way I can get the to come back online is by doing the following:

1. Set the radio admin status to "disable" and apply

2. Turn off CDP

3. Reboot the AP

Wait until the AP is back online and registered on the controller

4. Enable the radio admin status and CDP.

If I do not remove the CDP setting I cannot bring the radio back to "UP". I know we had previous issues with autonomous 1242 APs that did not like CDP being enabled. Have I perhaps got a bunch that are like that? Despite these having operated as autonomous APs they are AIR-LAP1242 from the factory. Any ideas?

[Scott Fella]

Tina,

I would just disable CDP for now and see if that's the issue, if so, then open a TAC case and see. Make sure that the AP and switch is negotiating the correct power also, especially when the radios goes down. You might just have to manually set the power on the PoE ports.

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[E07837_2]

Thanks for your answer. The APs are all connected via power injectors not PoE so it should not be an issue with power negotiation? I was hoping no to turn off CDP but I have to admit that it is the most likely culprit. Will try it.

[Scott Fella]

Have you tired setting this?

Thanks,

Scott

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[E07837_2]

Very difficult to see the image but if you mean the power injector setting then no, I haven't tried that. I guess we could try it. Just strange that we have 30 AIR-LAP1242s that are fine with the same settings and around 12 that are not. Thanks for the suggestion.

[Scott Fella]

I agree... When I have had issue with access points, the best solution for me was to delete all the images from flash and upload a new rcv image so that the ap is like brand new and have the ap pull the image down from the WLC. You can try it with a few along with the option I showed you to see if one or both fixes the issue. Or maybe not, but worth the try.

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[Scott Fella]

Also you should console/telnet/ssh to the AP and see if there are any crash file. Sometimes there can be many crash files that you run out of room in flash and that causes issues.

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