Access Provisioning and N+1

[Matthew]

I have setup 3 new controllers in and N+1 configuration. Two are active and one is an HA-SKU backup controller which either of the primary's can failover to. The setup looks good and has been verified. Now it is time to provision access points. I have about 220 access points which sit in a different VLAN, and believe I need to configure a DHCP option to point towards a controller which brings these questions to mind. (I'd like to break these up between the primary controllers, 110 each)

If I create a DHCP option that forces the AP to register with one controller doesn't this defeat the purpose of N+1?

Or

After the AP botos this will allow me to provision it and then I can specify one of two primary's and the backup controller?

If I specify the primary controller for an AP which is booting via DHCP with an option to point it to the first controller will the AP config override that and allow it to operate on the other primary controller which I just defined?

The controller config was fairly easy, but this is where I got confused.

[Noor Shukri]

Hi Matthew,

So this is the setup:

Controller 1 <--> Controller 2 <--> SKU controller

220 APs in different vlans

now you want to laod balance the APs between the two active controllers and keep the SKU as backup for all the APs.

Use DHCP optin 43 to help the APs on each VLAN to learn about that controller

The AP will learn about this WLC and will join it

For other APs in different VLAN let them learn the IP for the other WLC and they will join it.

After the APs joined the correct WLC, you can add the backup controller for them (SKU) from the GUI

If you want each WLC to exculsively allow particular APs to join (and don't accept the other controller APs) you can use AP policy (security -> AAA -> AP policy)

Keep in mind that SKU WLC is just backup and wont allow APs to join if the primary WLC is active hence it wont affect the load balancing

After the AP joins the WLC you can indeed change the primary/ secondary WLC (Wireless -> access point -> select this one -> HA ) or you can do it globally (wireless -> access point -> global configurations -> HA part )

I hope this answered your question!

Cheers,

Nour

[Matthew]

Thanks for the response. Everything is up and working so far. I am activating the VLANs that the ap's sit on and am seeing them on the controllers. However I am seeing then come up on the sku controller along with the two primary's. After I set the primary and backup on the AP's they transfer back to the conroller I would like them on. Not sure if this is normal during provisioning or not. 

[Noor Shukri]

This sku controller ... is it hardware or software sku (new code feature 7.5/ 7.6) or is it a standalone wlc with 220 licence ? How did the APs learned about it ? Did you add it to the dhcp? Dns? Same subnet as one vlan used by some APs?

[Matthew]

It is 7.6. I had added to option 43, which I probably shouldn't have done but have already set all the AP's with their proper controllers and the backup controller now has no AP's associated to it. All the AP's are in remote VLANs. I will be doing a failover test this weekend to make sure they fail over and back again.

[Noor Shukri]

Sorry my question wasn't clear about the SKU ... I mean is it HA SKU box that wotks without licence for backup only? Or is it another standalone wlc with full licence that is logically sku ? If it standalone controller then it's totally normal to accept aps as there is no restrictions For more information about redundancy you can check this http://me2learn.wordpress.com/2014/07/03/wireless-redundancy-methods/

[Matthew]

Thanks for the response. Everything is up and working so far. I am activating the vlans that the ap's sit on and am seeing them on the controllers. However I am seeing then come up on the sku controller too. After I set the primary and backup they transfer back to the conroller I would like them on. Not sure if this is normal during provisioning or not.