Catalyst 9800-L Wireless Controller Upgrade in HA

[Electronic20]

Hi Community,

An upgrade of 2 Catalyst 9800-L Wireless Controllers in HA is going to be performed and it manages APs both in remote sites and in the central site. The current version is 17.6.4 and it is going to be upgraded to version 17.9.5. I have the following questions:

Can the upgrade be performed directly from 17.6.4 to 17.9.5? Or should previous jumps be made?

What would be the appropriate procedure for the upgrade?

If we upgrade to version 17.9.5, does this affect or modify any service or feature that we have in our current WLC?

When upgrading the WLC version, does this affect in any way the synchronization that we have with the AP equipment located in remote sites?

regards
Electronic

[Electronic20]

Hi Community,

Before upgrading, how do I backup the configuration of the 2 WLCs in HA:

Is it just saving the show running-config?

Is the HA configuration of the 2 WLCs contained in the show running-config?

Regarding the IOS upgrade of the 2 WLCs in HA, if some functionality does not work, how do I perform the rollback to take it to the old IOS?

regards

Electronic20

[marce1000]

  - Just save the running configuration to an external  repository,  syncing to HA partner is handled internally.
     Regarding functionalities before and after ; use this procedure (CLI) show tech wireless and feed the output from  that Wireless Config Analyzer
     do not use a simple show tech for this procedure
                             (and to be done ,before and after the upgrade)

  M.

[Electronic20]

Hi @marce1000 

If for any reason the upgrade to the new IOS of the WLC C9800 does not work correctly.

What would be the rollback procedure? Would it be to return to the old IOS?

[marce1000]

 - There is no special rollback procedure needed ; the controller will stay at the current version,

 M.

[Electronic20]

Hi @marce1000

I change my question, how would a downgrade of the WLC be?, just upgrade the old IOS?

regards

Electronic20 

[Electronic20]

Hi Community,

From the WLC C9800 how can I update by AP groups and by a single AP?

There are more than 250 APs

How can I downgrade the IOS of the WLC C9800 in HA? That is, lower the IOS version from a current one to an older version in case of a problem with the new IOS version.

Your kind support

regards

electronic20

[Leo Laohoo]

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@Electronic20 wrote:
From the WLC C9800 how can I update by AP groups and by a single AP?

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Please read about a feature called "Hitless Software Upgrade (N + 1 Upgrade)":  Upgrade Software on Catalyst 9800 with N+1 Rolling AP Upgrade

Read it.  Understand it.  

We have done multiple WLC firmware upgrade using this process and it works.  We upgraded about 2900 APs to a WLC that affected cannot-afford-a-WiFi-outage campus with 10k daily wireless clients.  We performed the upgrade during business hours (started at around 10am).