Wireless Access

Dear Sir/Madam,

We would like to backup the Locals by the Master and the Backup Master. We plan to configure the Locals as "Active" in the HA group and configure the Master as "Standby", but we don't know how to handle the Backup Master. Could we just configure it in the HA group? If we put the Backup Master, as "Standby", in the HA group, does the AP connect the Master first?

Thanks,

Sam

Hi Sam, 

One quick note... Deployments that require master controller redundancy should continue to use an existing VRRP redundancy solution.

But it is possible to use HA configure HA in Master-standby mode. It is not recommemded to put the Master or the Backup-Master controller as HA standby. 

If the AP reboots, during the master-discovery, it has to first come up on the Master controller. If the Master is an HA standby, it may not accept the primary tunnel from the AP. So the AP will not come up on the Master after the reboot if the Master controller is on Standby mode. I just tested this quickly to verify it. 

If you would like to use HA with Master-Redundancy, I would recommend, Local as HA-Active, Master and the Backup-Master as HA-Dual. 

Make sure that your HA group-profile is configured in this order. 

HA group-member IP address <Local-ip> active
HA group-member IP address <Master-IP> dual 

HA group-member IP address <Standby-IP> dual 

The LMS IP on the AP system profile as the Local controller's IP. 

Thanks, 

Rajaguru Vincent 

Dear Rajaguru,

Thanks for your quick reply. We will continue to use VRRP in Master redundancy. 

Regarding HA (AP Fast Failover), what is the behaviour in case the AP connects to the Standby Master when it's still in standby mode? Will the AP retry to connect to the Standby Master? 

Thanks,

Sam

Hi Sam, 

If the AP connects to the Standby Master when the controller is still in standby mode, the AP will re-try to connect to the Standby Master. But, here the AP only knows the IP address of the controller. The AP doesn't know if that controller is in Master-role or Standby-role. 

And the controller, when it is on standby-role, will not accept connections from AP. You'll see the below WARNING on the Standby controller logs when AP requests are received. And the AP will not come up on the Standby controller. 

Dec 1 01:37:47 stm[1894]: <305018> <WARN> |stm| Switch is backup master; ignoring AP request
Dec 1 01:38:48 stm[1894]: <305018> <WARN> |stm| Switch is backup master; ignoring AP request

So, mixed-mode deployment of VRRP master redundancy and ha-lite is not supported.

You can find the below note in the user-guide for reference,
"High Availability:Fast Failover provides redundancy for APs, but not for controllers. Deployments that require master controller redundancy should continue to use an existing VRRP redundancy solution."

Thanks,
Rajaguru Vincent 

Thanks a lot for your information.