Cisco 9800 No GUI after HA Failover

[shawn.pattison]

We have two Cisco 9800-L-F Wireless Controllers in an HA pair with RP.  When there is a failover event the GUI is no longer available.

You can navigate to the GUI page and login but after that all you see is a white screen.  

We still get pop-up notifications on the blank GUI screen and if you click on a pop-up the event screen will open up and can see it but once you close that window the main GUI screen remains blank.

I've tried in Edge, Chrome, Firefox and Brave and get the same results.

[jagan.chowdam]

What is the controller version? 

Have you tried different computer/laptop to access the controller? 

Can you SSH into the current primary controller? 

Can you confirm the current primary WLC has TrustPoint configured for HTTPs? Refer the section "Dealing with Trustpoints" from the following best practices guide

https://www.cisco.com/c/en/us/products/collateral/wireless/catalyst-9800-series-wireless-controllers/guide-c07-743627.html#:~:text=from%20the%20GUI%3A-,Web%20user%20interface%20(WebUI),-WebUI%20uses%20VTY

Add the below commands, it should fix this GUI slow/hang problem.

! 

service tcp-keepalives in

service tcp-keepalives out

!

line vty 0 50

!

CJ

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[shawn.pattison]

Cisco IOS XE Software, Version 17.09.03
Cisco IOS Software [Cupertino], C9800 Software (C9800_IOSXE-K9), Version 17.9.3, RELEASE SOFTWARE (fc6)

We've tried a different PC/Laptop to try accessing the GUI and still see only the white screen

Ran the "service tcp-keepalives" command s and "line vty 0 50" then reloaded the controller.  After reload GUI came back.

Initiated a failover from controller 2 to 1.  Controller 1 reloaded and then the GUI came back up.  

[jagan.chowdam]

Good to hear the issue resolved.

CJ

[Rich R]

@shawn.pattison that suggests you never read the Best Practices guide (link below) so now is probably a good time to go through it and see what else you've missed.
Also use the config analyzer (link below too) to check your config and highlight any other problems it spots.