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

[Scott Fella]

I think your questions can be answered by reviewing the release notes. This is something everyone looks at to ensure the upgrade path and any new caveats and resolved caveats.

https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/release-notes/rn-17-9-9800.html#Cisco_Concept.dita_59a2987f-2633-4630-8c7b-a8e8aecdeaf7

Typically you would test if you had another controller to validate everything works fine with the configuration you have and the environment you have.  

Read the release notes so you are familiar and see if you still have any questions.  What works well for one might not work well for others.  That is why testing is very important and allows one to test the upgrade depending if you have one controller, SSO or N+1.

[Scott Fella]

Also, if you have a valid support contract, you can open a TAC case and have them on a call during your upgrade.  That might help you if you are not comfortable, or if this is the first upgrade you are doing on this environment.

[Leo Laohoo]

Direct upgrade, from 17.6.X, to 17.9.5 is supported -- Upgrade the ROMMON while it is possible.

Are both controllers in a Mobility Group?  

Do the controllers have SMU/APSP/APDP installed?

[Electronic20]

Hi @Leo Laohoo 

Both controllers are in HA, this is their configuration:

I don't think there is one, but could you give me a brief explanation of what SMU, APSP and APDP mean and what function they have?

regards

Electronic20

[marce1000]

 @Electronic20    FYI : https://www.cisco.com/web/Cisco_IOS_XR_Software/pdf/SMU_FAQ.pdf

                                   + An APSP is an  AP Service Pack 
                                      APDP: Support for new AP models without introduction of new hardware or software capabilities.

  M.

[Leo Laohoo]

If the controllers are in an HA SSO, then there is no way to "minimize the downtime".  The controllers will reboot (around 7 minutes) and the APs will reboot (another 7 minutes). 

If the two controllers were in an N+1 and both units are in the same Mobility Group, there is a way to "minimize the downtime" by using a feature called Hitless Upgrade.  This following scenario is how Hitless Upgrade (we've used it several times on 9800-80 & 9800-L and we have not seen any issues) works: 

NOTE: 

• Assume WLC-1 is Active and WLC-2 is Hot Standby.  
• Assume all APs are in WLC-1 and WLC-2 has ZERO AP count.  
• WLC-1 & WLC-2 are in a Mobility Group. 

1.  Upgrade the WLC-2 firmware first. 

2.  Once Hitless Upgrade is initiated in WLC-1, WLC-1 will start to move APs (from WLC-1) to WLC-2 in "batches" based on the Iteration selected (5%, 15% or 25%).  APs joining WLC-2 will download the new firmware and reboot.  When WLC-2 confirms these APs have joined WLC-2 and on the correct firmware, the next batch of APs are moved to WLC-2 until all APs have joined WLC-2 and are on the correct firmware.

3.  As soon as WLC-1 has no more APs, WLC-1 will reboot to the desired firmware version. 

4.  When WLC-2 confirms that WLC-1 is running the same firmware (as WLC-2) and WLC-1 has joined the Mobility Group, WLC-2 will reverse the process and send all the APs back to WLC-1.  

[Electronic20]

Hi Community:

Apart from upgrading WLC 17.6.4 to 17.9.5, is it also necessary to load SMU, APSP and APDP? And if so, what improvement would it bring?

regards

Electronic20

[marce1000]

        >...Apart from upgrading WLC 17.6.4 to 17.9.5, is it also necessary to load SMU, APSP and APDP?
  - Normally not , unless there are specific SMU , APSP and APDP attached or provided with 17.9.5.
    The decision to install these or not depends on reviewing the (release) notes of those and check
    for specific circumstances and conditions that may apply to your environment , 

 M.

[Electronic20]

Hi @Leo Laohoo 

You mention updating RMON, how do I update it and where do I download that firmware?

Is it necessary to update SMU, APSP and APDP?

en mi caso no es un Mobility Group ni esta en N+1, la solución que se tiene es un HA.

regards
Electronic20

[Leo Laohoo]

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@Electronic20 wrote:
You mention updating RMON, how do I update it and where do I download that firmware?

---

ROMMON upgrade and firmware upgrade can be done in one reboot.  I do it all the time.  

---

@Electronic20 wrote:
Is it necessary to update SMU, APSP and APDP?

---

Do not go blindly installing SMU/APSP/APDP if there is no operation requirements, like fixing a bug, because applying APSP/SMU/APDP, guaranteed, will introduce a new level of bugs.  One of those bugs can cause the WLC to boot into ROMMON because the switch/WLC is unable to automatically remove previous SMU installed.  

---

@Electronic20 wrote:
en mi caso no es un Mobility Group ni esta en N+1, la solución que se tiene es un HA.

---

Keep monitoring the control-plane memory utilization due to HA SSO.

[Electronic20]

Hi @Leo Laohoo 

Thank you,

I have a question about the ROMMON update, to confirm, when I update the WLC IOS, is the ROMMON automatically updated?

regard

Electronic20

[Leo Laohoo]

ROMMON is a manual upgrade.

[Electronic20]

Hi @Leo Laohoo 

Cual seria el procedimeinto de actualizar el ROMMON en un 2 WLC en HA SSO?

[Leo Laohoo]

upgrade rom-monitor filename bootflash:ROMMON_filename all
upgrade rom-monitor filename bootflash:ROMMON_filename chassis standby 0
upgrade rom-monitor filename bootflash:ROMMON_filename chassis standby F0
upgrade rom-monitor filename bootflash:ROMMON_filename chassis standby R0