Difference between N+1 HA model and traditional secondary/Tertiary Cisco 5508 Model.

[Puneet Gupta]

Hi Team

we are going to implement N+1 HA cisco WLC high availability for that we have procured one WLC 5508.

However i am not able to find out difference between N+1 and secondary WLC configured under each AP in wireless tab ?

As per my understanding both are giving the same functionality. Can you please highlight any difference ?

Thanks....

[Rasika Nayanajith]

This should be useful to understand this

http://www.cisco.com/c/en/us/td/docs/wireless/technology/hi_avail/N1_High_Availability_Deployment_Guide/N1_HA_Overview.html

HTH

Rasika

**** Pls rata all useful responses ***

[Puneet Gupta]

Hi Rasika

Thanks a lot for the information but i have this and read this document.

However i just want to know  the difference between these two ..

[Scott Fella · Accepted solution]

There really isn't any difference from doing HA N+1 and having a WLC with licensing except when you have an HA Sku WLC, you shouldn't place any access points in that controller and only use it as a backup. With two licensed WLCs for example, you can have half your AP's on one and the other half on the other WLC. HA Sku is used only as an N+1 and a backup.  Hope this helps you understand the difference. 

-Scott

[Puneet Gupta]

Hi Scott

Thanks a lot for the information .This is very useful.However i need one small clarification..

There are three redundancy model..

1+1  where you need one WLC acts HA SKU

N+1 Where one WLC is backup for all N WLC

Third and last one is , where we mention the secondary and tertiary WLC under wireless tab.

So i want to know the difference between second and third option.

Thanks

[Scott Fella · Accepted solution]

There is no difference with the 2nd and 3rd. They need to all be setup the same way and what you do is configure the AP which would define what the primary, secondary and tertiary WLC is. So an ap at site A can have WLC1 and the primary, WLC2 as the secondary and WLC3 as the tertiary. Then you can have site B as WLC2 as the primary, WLC3 as the secondary and WLC1 as the primary. You define it so there is no real difference. 

-Scott