9120AXE-B gets controller rejected when trying to reach out.

[williamsonjason]

Hello all, 
New WLC c9800 w/ new APs
finally figured out how to statically assing an IP
I gave it a capwap primary base to point it to the controller
It reaches the controller but then gets:

WLC9800 is on v17.3.4..40
AP is on v17.6.4

[*07/13/2023 00:52:09.0330] Discovery Response from 10.x.x.x
[*07/13/2023 00:52:09.0330] Discovery response from MWAR 'C9800L-WLC10-DES' running version 17.3.4.40 is rejected.
[*07/13/2023 00:52:09.0330] Failed to decode discovery response(status = 4).
[*07/13/2023 00:52:09.0330] CAPWAP SM handler: Failed to process message type 2 state 2.
[*07/13/2023 00:52:09.0330] Failed to handle capwap control message from controller - status 4
[*07/13/2023 00:52:09.0330] Failed to process unencrypted capwap packet 0x558b448000 from 10.3.2.10
[*07/13/2023 00:52:09.0330] Failed to send capwap message 0 to the state machine. Packet already freed.

[Leo Laohoo]

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@williamsonjason wrote:
WLC9800 is on v17.3.4..40
AP is on v17.6.4

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Look at the back of the AP for the serial number "plate".  Look at the date of manufacture.  Was the AP manufactured on September 2022 (and later)?

If it is, please read FN72424 - Later Versions of Some Wi-Fi 6 Access Points Fail to Join the WLAN Controller.

[Rich R]

You really shouldn't be using 17.3 at all because it's almost EOL and already no more bug or security fixes.
Upgrade the WLC to latest code as per the TAC recommended link below before you do anything else!
And then make sure you update regularly to keep the WLC on supportable and secure code.

[williamsonjason]

17.9 helped, thanks!

@Leo Laohoo  - will i need to install an AP service pack to get the old 3702s to work on this new controller? My goal is to put these new controllers on the network, migrate all the 3702s, and then send my guys out to swap the old APs with new APs after that. 

[Rich R]

> will i need to install an AP service pack to get the old 3702s to work on this new controller?
No. As per the release notes 17.9 has supported 1570, 1700, 2700 and 3700 Series Access Points since 17.9.3 so as long as you used the latest release as per TAC recommended they'll just work.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-9/release-notes/rn-17-9-9800.html#whats-new-1793

However, again as per TAC recommended, you may want to install the APSP for the additional fixes that it provides.

[Leo Laohoo]

17.9.X and 17.12.X will support 2700/3700 natively.