WLC 5508 pair, redundancy not working

[mhmservice]

Hi all

I have 2x 5508 in SSO mode

I performed a failover test (by executing command "redundancy force-switchover" and after the standby controller rebooted, HA seems to no longer be working:

From active controller

(Cisco Controller) >show redundancy summary
Redundancy Mode = SSO ENABLED
Local State = ACTIVE
Peer State = UNKNOWN - Communication Down
Unit = Primary
Unit ID = 00:07:7D:BF:E1:20
Redundancy State = Non Redundant
Mobility MAC = 00:07:7D:BF:E1:20
BulkSync Status = Pending

From standby controller

(Cisco Controller) >show redundancy summary
Redundancy Mode = SSO ENABLED
Local State = MAINTENANCE
Peer State = UNKNOWN - Communication Down
Unit = Secondary
Unit ID = 88:43:E1:7D:D0:80
Redundancy State = Non Redundant
Mobility MAC = 00:07:7D:BF:E1:20
Maintenance Mode = Enabled
Maintenance cause= Peer RP is not reachable or Hardware model/Software version mismatch

I can't ping between the RP port IPs (not sure if I was able to before)

The ports are connected over a VLAN but i've checked all the basic stuff and I can see both MAC addreses on either switch, so the config must be OK there.

Does anyone have any suggestions what the problem could be? As stated it was working fine until I forced failover ..

[balaji.bandi]

Maintenance cause= Peer RP is not reachable or Hardware model/Software version mismatch

Not sure what is the version, check the Layer 2 connectivity.  check on the switch ports side any error disabled or port gone down ?

some reference :

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-7/High_Availability_DG.html#pgfId-43282

[Scott Fella]

Console into both and verify that the code matches. Maybe something was not saved when you rebooted the unit. If you don’t know if it was working previously, you might just have to disable SSO and go through the steps again to make sure all the requirements were met.

[MHM Cisco World]

RP must be direct connect between WLC active/standby 

[joyaljp]

Hi,

Are the two WLC's in two different locations and is that the reason why you're using a VLAN to connect the RP ports? 

[mhmservice · Accepted solution]

WLCs are in 2 different halls of a datacentre so the VLAN is on a switch

Problem was VLAN not allowed on the trunk between the WLCs!

Issue solved and HA is working fine now, no problem with the WLCs