Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

Flex AP randomly loses configuration on Cisco 7500 Flex WLC in HA with 1800+ AIR-CAP1702 APs running 8.2.100.0

Dear reader,


I am in need of some advice! We have the above setup running and are stumbling upon a very annoying issue.

Flexconnect AP's are randomly losing their configuration and I am figuratively pulling my hair on this one. The hostname will change to default; AP-<mac>. We will usually find out about this on incident basis; a branch location will complain about coverage or bad connectivity. After troubleshooting, we often see that an AP has lost its configuration and is obviously not functioning properly. It will have to be replaced or reconfigured via a console session.. 

What we have tried

The 7500 Flex is running version: 8.2.100.0

Due to the deferred status of 8.2.100.0 I have setup a test-5508 WLC (single controller) to test suggested software version 8.2.151.0 and migrated 20 odd AP's to this WLC. This ran fine for a couple of weeks but then the issue recurred which seems to rule out software version and/or High Availability setup. On a side note: we do have multiple WLC controllers managing other AP's (different models and not in Local mode, not Flexconnect mode).

The AP's all use WLAN VLAN mapping and VLAN support. They are connected to 2960 switches and routed by a 891F router. 

Initially will receive a DHCP assigned address by the router, but we have configured all AP's to a static IP. 

The AP's are at branch locations. When they have lost the configuration they are only accessible via a console connection. So the only option is to replace them or use a console cable. 

A shut/no shut will force a restart but the issue persists. The router will still hand out an address to the AP.

Sometimes an AP will appear normal on the WLC i.e., will have a hostname and is visible on the WLC. After performing a reset on all AP's of a specific Flex group using config ap reset on the WLC for every AP in that group, the AP might not reappear or rejoin the WLC. Using sh cdp nei on the switch will verify that the AP has reset to default configuration. This gives rise to the question, was the AP functioning normal before the reset or did it already malfunction and did the reset 'show its actual state'.

Has anyone experienced similar issues in a setup like this? (Flexconnect specifically). 

Highly appreciate your feedback. Thanks in advance. 

2 ACCEPTED SOLUTIONS

Accepted Solutions
VIP Purple

I would suggest you to

I would suggest you to upgrade software version to 8.2.161.0 and see if problem is there. Current version you are running is the first release of 8.2 code train and have lot of defects

http://www.cisco.com/c/en/us/td/docs/wireless/controller/release/notes/crn82mr6.html

HTH

Rasika

*** Pls rate all useful responses ***

Re: I would go with 8.2.160.0

There are more than 170 bugs fixed in 8.2.160 which is the reason Rasika refers to that release I assume. However, using flex-connect might be a good reason to stick with 8.2.151 for now due to two bugs in 8.2.160.

 

Having other versions of code on back-up controllers can cause issues when there is a connectivity issue between the primary controller and access-point. Not only the change of the software on the access-point, but also slow failover, losing configuration due to incorrect AP/Flex groups and version specific bugs being triggered.

 

I have not seen your specific issue myself, however I never use static IP on access-points which might be one of the triggers.

5 REPLIES
VIP Purple

I would suggest you to

I would suggest you to upgrade software version to 8.2.161.0 and see if problem is there. Current version you are running is the first release of 8.2 code train and have lot of defects

http://www.cisco.com/c/en/us/td/docs/wireless/controller/release/notes/crn82mr6.html

HTH

Rasika

*** Pls rate all useful responses ***

Hi Rasika,

Hi Rasika,

Actually the suggested version is 8.2.151.0 which I have installed on a separate 5508 WLC.

I have migrated AP's to this WLC using the HA options. But we had one occurrence of the issue even with newer software.

The old 8.2.100.0 is still in the backup slot but that shouldn't be causing issues.

I have found a workaround for this issue.

The AP which has lost it's global config, still keeps the static IP and thus DHCP discover request is not sent (i assume).

I see broadcasts on the switch when I sh log, also ports UDP 5246 and 5247.

These broadcasts go nowhere it seems..

I have configured ip helper address on the capwap vlan management interface and also manually configured ip forward-protocol on the router.

After configuring this the AP joins the WLC again. For us however, this is still a workaround. So I'm still looking for a solution.. We will first upgrade to 8.2.151.0 and take it from there.

VIP Purple

I would go with 8.2.160.0

I would go with 8.2.160.0 instead of 8.2.151.0 (unless specific reasons provided)

HTH

Rasika

Re: I would go with 8.2.160.0

Hi Rasika,

 

Thanks again for your feedback. Could you shortly elaborate why you would prefer 8.2.160.0 over 8.2.151.0 ?

 

Cheers

Re: I would go with 8.2.160.0

There are more than 170 bugs fixed in 8.2.160 which is the reason Rasika refers to that release I assume. However, using flex-connect might be a good reason to stick with 8.2.151 for now due to two bugs in 8.2.160.

 

Having other versions of code on back-up controllers can cause issues when there is a connectivity issue between the primary controller and access-point. Not only the change of the software on the access-point, but also slow failover, losing configuration due to incorrect AP/Flex groups and version specific bugs being triggered.

 

I have not seen your specific issue myself, however I never use static IP on access-points which might be one of the triggers.

193
Views
0
Helpful
5
Replies