APs Cannot join the Controller

[Allan001]

Hi all,

My APs can't join the C9800-CL ver 17.6.5. The controller is run on a HyperV server.

1) Certificate is configured, and I see it with: sh wireless management trustpoint. 

2) I configured the DHCP scope in the controller 

3) Checking the DHCP binding - it shows that 2 APs have been allocated addresses, and I can ping those 2 APs from the controller. However, the APs are not joining the controller. 

4) Wireless management is an SVI in controller under VLAN 10

5) Gig 2 is configured as a trunk, and VLAN is allowed on Gig2

6) The port-facing APs are configured as access with VLAN 10

Additionally, I haven't registered the controller with a license yet, so I'm uncertain whether it's necessary to do so for the APs to join. The AP model is C9115xai. In the logs, I cannot see any CAPWAP log. And to register the AP license to the controller using a smart account. I noticed some IP addresses need to be configured for the controller to communicate with CCSM - where would I get those IP addresses?

Any help is appreciated.

Thank you,

[balaji.bandi · Accepted solution]

C9115xa  - what version of AP ? new model v5 or more  need Cat 9800 should be 17.8.X or 17.9.X

Also post complete log from AP console.

[Allan001]

Hi Balaji,

I really appreciate your taking the time to respond. The APs are at a remote site - I will get a tech to drive to the site tomorrow to console into the AP. I also asked the customer to check the UDP ports 5246 & 5247 are not blocked on the the FW. I found out that there is an FW in between the controllers and the switches with APs. Once I have the AP console output tomorrow, I will share it here

Thank you

[balaji.bandi · Accepted solution]

Sure get the information so we can assist better.

[Allan001]

Hi Balaji,

Thank you for the info. The Tech went to the site and could not do anything as the whole area had no power due to a transformer that blew up last night. Hopefully, by tomorrow it will be sorted them on Monday I can start working again.

Thank you so much.

[marce1000]

  - Check controller configuration with  show  tech wireless  (CLI command) and feed that output into : https://cway.cisco.com/wireless-config-analyzer/  , check AP model and verify if this FN might be applicable : https://www.cisco.com/c/en/us/support/docs/field-notices/724/fn72424.html  , for Cloud controller AIR-DNA license for APs is mandatory.

          Also check controller logs when the APs try to join , advised too  : check AP boot process with console attached, check for errors if any.

 M.

[Allan001]

Hi Marce,

Many thanks for providing solutions. Much appreciated. I will try the solutions you provided above. Once again, thank you for your time and effort in trying to help. 

Thank you

[Scott Fella · Accepted solution]

First off... make sure you follow the guide and you have met the requirements for the size of the controller.  Also, when using a 9800-CL, you really don't want traffic to tunnel back.  You wan to setup the management and the wireless management which I usually use the management also as the WMI.  License is not an issue here because you probably purchased the license when you bought the ap... tied to the ap.  Place the ap on the same subnet as the controller management to at least validate if the ap can join.  Then you can move the ap to any other subnet and you don't have to create any new SVI on the controller.

https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/9800-cloud/installation/b-c9800-cl-install-guide/b-c9800-cl-install-guide_chapter_01011.html

You can also search the internet for "cisco 9800-CL Hyper-V" and look at blogs and or videos on the setup. 

[Allan001]

Hi Scott, 

Thank you so much for your contributions. I really appreciate it. Currently, the APs are placed in the same vlan as the management. When configuring the controller, I used a cisco guide on deploying the C9800-CL on a HyperV. I am not sure what I am missing. I also watched youtube videos, and it looks like I configured the exact same config. The difference is mine is not working.

Once again thank you so much. 

[Scott Fella]

Console into the ap and attach that to the thread.  That should show a message why the ap con't join the controller.

[Allan001]

Hi Scott, 

I will get a tech to go to the site and share the output.

Thank you.

[Scott Fella]

@Allan001 a couple of things also.  I would configure the DHCP on the controller, ip helper should be on the SVI on the upstream L3 device and you should use an external DHCP server that all other devices use to obtain an ip address.  Also it doesn't hurt to register the controller to the Smartlicense portal, it only take a few minutes as long as the Smartlicense is in your portal.

Make sure the tech captures this from a few ap's also and you should check to make sure the switch port is configured properly so that the ap is on the management/wireless management vlan.  Doesn't hurt to provide the port configuration also, so that others can review and provide feedback.

[Allan001]

Hi Scott, 

Thank you for the info. The Tech went to the site and could not do anything as the whole area had no power due to a transformer that blew up last night. Hopefully, by tomorrow it will be sorted them on Monday I can start working again.

Thank you so much. 

[Scott Fella]

Okay... thanks for the update.

[marce1000]

 - Adding to my initial reply , if problems persist then start using these tools too : https://logadvisor.cisco.com/logadvisor/wireless/9800/9800APJoin

 M.