Wireless C9800 update Redundancy settings

[Scorpioo]

Hi team,

we have installed c9800 HA pair 2 months ago, running 17.12.4 version.

We are facing now random reloads of standby WLC every few hours with this info:

Reload History:

Reload Code: Reload
Reload Description: Reload Command - RIF: Bulk Sync, system report at bootflash:core/XXXXX
Reload Severity: Normal Reboot
Reload Time: 05:21:52 CEST Wed Apr 9 2025

As active WLC could see keep alive missing packets in logs, we got recommendation to increase keep alive timer in GUI (Administration -> Device -> Redundancy -> Keep alive timer) to 10 (currently set to 1).

My question: would this update of running HA pair cause some downtime for active WLC / HA pair / associated clients? 

Also, is there a way how to test RP cable (direct connection between A/S WLCs) to prove cable issues or we should just exchange cable?

Thank you

[Scorpioo]

Output of show platform hardware slot R0 ha_port interface stats attached

[marce1000]

  - @Scorpioo Nothing special seen ,as stated also check the interface counters on the switch ports where the RP ports are connected to ,

  M.

[Scorpioo]

What do you mean by check the interface counters on the switch ports where the RP ports are connected to?

RP ports on WLCs are connected to each other via cable, right? 

We are using Gi0 for MGMT of WLCs and then TenGig port for connection to uplink switch. There are no interface input/output errors or CRCs visible.

[marce1000]

  - @Scorpioo   >...RP ports on WLCs are connected to each other via cable, right? 
                           Yes , that is  supported topology too.  When the standby reboots check
                           for  crashdumps on it's bootflash  ; checkout the commands below the first one
                           having priority

                                       dir bootflash:/core/ | i core|system-report
                                             show version | inc reload
                                            show platform
                                            show inventory
                                           show environment

    (Remember ; to be executed on the Standby in this case)

   M.

[Leo Laohoo]

CSCwo69177