1020s dropping from Controller

[Patrick McHenry]

Hi,

In the past two weeks I have seen most of our 1020s drop off the Controller and then join again. They are sometimes down for several minutes. Each 1020 has gone down only once and then it stays up but, it seems really strange to me that they are doing this. I looked at the log yesterday after one dropped and this was the message from the Controller:

AP's Interface:1(802.11b) Operation State Down: Base Radio MAC:00:0b:85:54:da:70 Cause=Max Retrasmission

Any ideas what this is telling me and why this dropping might be happening?

Thanks, Pat.

[Federico Ziliotto]

Hi Pat,

I remember our previous discussion on another thread ;-)

https://supportforums.cisco.com/message/3259003#3259003

After some further research on that one and on this error message, could you please confirm which version you are running on the WLC?

We may be facinf something related to the bug CSCsm78567 for example:

http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCsm78567

Regards,

Fede

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[Patrick McHenry]

Thanks. The image is 4.2.112.

[Patrick McHenry]

From the link it looks like it is a bug. Do you think I could disable CDP on the switchport instead of the AP?

[Federico Ziliotto]

Hi Pat,

The bug is causing a memory leak due to the CDP processing on the AP.

So disabling CDP on the switch, but leaving it enabled on the APs, may still trigger the issue.

The safest way would be to disable CDP on the APs from the WLC to verify whether you are really hitting that bug:

config ap cdp disable

Regards,

Fede

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[Patrick McHenry]

Sorry about this but, I have a couple more questions:

Will the AP lose connectivity when disabling CDP on the AP from the Controller? Thanks, Pat.

[Federico Ziliotto · Accepted solution]

Hi Pat,

Disabling CDP on the AP should have no impact on the connectivity with the WLC.

I also tested this quickly on an AP in our lab and no disruptions were observed in the communication between the AP and the WLC.

Regards,

Fede

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[Patrick McHenry]

Thanks Federico.

[Federico Ziliotto]

Sure Pat,

Hope this helps you out with your issue.

Feel free to ping us back in case you'd need further assistance with this wireless setup in the future.

Regards,

Fede

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[Patrick McHenry]

Hey Fede,

Do you know if I could accomplish the same thing by going into the GUI and unchecking the Cisco Discovery Protocol under Wireless>click on AP>goto advanced tab?

Thanks

[Federico Ziliotto · Accepted solution]

Hi Pat,

Yup, that should do exactly the same thing as the command I previously pasted.

Regards,

Fede

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