9800 HA N+1 Retaining AP Tags

[awatson20]

We are in the process of converting to Cisco 9800 controllers and are testing the HA failover in a N+1 deployment.  When AP's are failed mover to the secondary HA controller, they are falling into the default policy, site, and rf tag group.  On the HA controller, we have the policy tag, site tag, and RF tag defined, but this is still not working correctly.  Any input on how to ensure that AP's land in the correct tags on the HA backup controller?  We checked on the box for enabling tag persistence but that did not seem to work.

[marce1000 · Accepted solution]

 -  You may  check the configuration of both controllers using the command show tech wireless ; feed the output into :
                                                                      Wireless Config Analyzer

 Also recommending to configure ap  tag persistency enable to have the configured tags saved on the AP automatically ; CLI based execution is better  , sometimes GUI has bugs ,

 M.
                

[awatson20]

Do this(ap  tag persistency enable) on both the primary controller and the secondary HA?

[marce1000]

            - Yes , also use the mentioned WirelessAnalyzer procedure , it can be very helpful , 

 M.

[awatson20]

Enabling the ap tag persistency in the cli seemed to work. One last question, on the HA backup controller, for locations with access points that will possibly failover, is it best practice to have all of the site tags / policy tags defined on the HA controller for all locations similar to how AP groups were used in AireOS? Or, can we rely on the AP tag persistence feature to carry over?

[JPavonM]

Which IOS-XE version are you running?

Cisco added ap tag persistency on 17.6.1 enabled by default so all APs will carry their tags to other N+1 WLCs unless there would be a static config for them with different tags (https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-6/config-guide/b_wl_17_6_cg/m_ap_tag_persistency.html?bookSearch=true)

[awatson20]

Both primary and secondary HA controller are on version 17.9.4a.  Does "Enable AP Tag Persistency" need to be checked on both controllers?

[marce1000]

 - Added reply (ref) : https://www.cisco.com/c/dam/en/us/td/docs/wireless/controller/9800/17-4/deployment-guide/c9800-n-plus-1-high-availability-wp.pdf
              Read paragraph :  Moving APs between controllers and preserving tags

 M.

[Rich R]

> Does "Enable AP Tag Persistency" need to be checked on both controllers?
Yes.
> all locations similar to how AP groups were used in AireOS?
Yes the config must be mirrored on each WLC which the AP could join.  The tag will persist on the AP but if the tag is not configured on the WLC then the AP will be forced back to default tags because the WLC doesn't recognise the tag.

That's the thing with N+1 redundancy - it's up to you to keep your WLCs running with the same config.