5500 Series WLC Work Cluster

[olgu arabaci]

I search how can i work two Controller on redundancy, i find high_availability article on site but this article says you should upgrade software at least 7.3 (my controller is 7.2). The thing that i wonder is can not we use redundancy feature on release before 7.3 ? if it was, which feature can i use for redundacy structure ?

And also i want to know; when i read high_availability article i saw one controller is being back-up controller and holding on standby. i understand that this controller not work unless active controller is crash. in other words the controllers  do not load balancing. i maybe wrong about this so i'm so glad if you lighting me. Thanks already for all replies...

[Sandeep Choudhary]

Hi Olgu,

If you want make redudncy with 7.2 then follow this procedure:

Configure primary and second controller on each access points.

Below lists the Access Point join order:

* The AP will associate first with its primary controller, assuming it has been primed.

* Upon failing with the primary, it will try to register with its secondary and then its tertiary.

* If there is no controller information primed in the AP, the AP will then look for a master controller.

* Finally, if there is no primed controller and no master controller, the AP will select the least loaded from all controllers that have responded to the discovery.

http://www.cisco.com/en/US/docs/wireless/controller/7.2/configuration/guide/cg_lwap.html#wpmkr1426782

Hope it helps.

Reagrds

Please rate helpful posts.

[olgu arabaci]

Thnx for the reply sandee;

I have a few questions;

1- When primary controller fail and AP register the secondry, are there any interraption for clients ?

2- what is the difference of primary and master controller ?

3- I return the first question when i use software latter 7.2,is the stand-by controller doing load balancing or not ?

4- What is the importancy of mobility group for controller ? I know when a clients change APs which are in the same mobility groups, they roaming and no interruption. What's more than this...

[Scott Fella]

1- When primary controller fail and AP register the secondry, are there any interraption for clients ?

Yes... If a WLC fails, all connection drops and the AP has to go through the discovery process.

2- what is the difference of primary and master controller ?

Master WLC is for initial staging which forces a new ap to join that WLC if reachable. Primary, secondary and or tertiary is the priority of wlc's you want that ap to join.

3- I return the first question when i use software latter 7.2,is the stand-by controller doing load balancing or not ?

If both wlc's has license, then you load balance the AP's by setting the primary, secondary and or tertiary WLC.

4- What is the importancy of mobility group for controller ? I know when a clients change APs which are in the same mobility groups, they roaming and no interruption. What's more than this...

It's also used for AP's to know about the other wlc's in the same mobility group for failover.

Sent from Cisco Technical Support iPhone App

[olgu arabaci]

So Scott;

Before 7.3 Can i make the redundancy structure the controllers without interruption ?

The previous post there is misunderstanding. I try to say i return my first post(but i say first question).

[Scott Fella · Accepted solution]

No.. There will be interruption. AP failover doesn't mean it will keep clients connected. Only with v7.5 and the Client SSO can this be achieved.

Sent from Cisco Technical Support iPhone App

[olgu arabaci]

Scott;

Today i try do redundancy on WLCs with using http://www.cisco.com/en/US/products/ps10315/products_tech_note09186a0080bd3504.shtml this article. When i enable SSO on both WLCs and connect with SSH i saw the connection problem between WLCs' redundant management interface. So i couldn't provide redundancy on WLCs. And when i enable SSO on WLCs, i lost GUI connection in normally. I execute "config redundancy mode disable" command on WLC which i choose redundant unit secondary. It works and now i can access this WLC on HTTP. But when i execute this command on WLC which i choose redundant unit primary, it wasn't work and i get an error message below;

"Invalid redundancy mode parameter provided."

How can i take all this back ? I want access both WLCs with HTTP.

[Scott Fella]

When using AP SSO, you can only access the primary WLC via GUI.  If you want to be able GUI into both WLC's, then AP SSO isn't for you.  You might want to look at HA N+1:

http://www.cisco.com/en/US/docs/wireless/technology/hi_avail/N1_High_Availability_Deployment_Guide.html

Thanks,

Scott

Help out other by using the rating system and marking answered questions as "Answered"

[Leo Laohoo]

How can i take all this back ? I want access both WLCs with HTTP.

Like what Scott said, when you enable AP SSO, you will loose GUI access to the redundant controller.  The only way for you to have access is via SSH and this is a limited-access-only and you can't enable Telnet.

The logic behind this is because the configurations to both MUST BE synchronize.  If someone makes changes to the redundant controller and forgets to make the same changes to the primary controller, chaos ensures.

Besides, in a AP SSO environment, why would you want to make changes to BOTH controller when you have the luxury of making changes in one controller and the system will synchronize the changes to the redundant pair.