Back UP Cisco Controller

[m.dridi89]

Hello,

i have two controllers 2504 in different sites so differnet subnets  and i would like to make the wlc's back up each other  so when wlc 1 goes down the aps from that wlc  join the wlc2 .

 can you please tell me how that could be done ? if the ap had to be flexconnect ?

is HA  need to make the managment subnets the same or could be done in our case (differents subnets) ?

[Scott Fella]

The only way this would work right now in your design is if all the WLAN's are configured for local switching.  If there is even one WLAN that is configured for central switching then you need that backup controller to be on the same site.  If the later is the case, then you can buy an HA sku 2504 and use that as the backup.  Hope this helps.

-Scott

[m.dridi89]

Thanks Scott,

So i need to make all the aps in flexconnect .in order to make that work ?

"then you can buy an HA sku 2504 and use that as the backup " you mean to put it on the same site as the wlc ??? 

[Scott Fella]

No you don't need to make everything in FlexConnect mode. I was only telling you how it can be done with one WLC and the limitations since you have multiple sites. If you have local mode AP's, then your better off getting an HA sku 2504 as the redundant unit in each site. This way you configure the HA controller exactly the same as the primary unit with the exception of the hostnames and IP address. 

-Scott

[Scott Fella]

Here is an HA N+1 guide you can review.

-Scott

[m.dridi89]

hi Scott

let me make it clair 

i had two sites site A: wlc A  and site B wlc B the aps are in local mode 

and the two site are connected via mpls 

i would like to make the ap from site A join the controller of site B when thier WLC goes down 

how can i do that without buyin au ha sku

[Scott Fella]

You would need to change the ap mode to FlexConnect and also design the environment for local switching. All access points would be on a trunk import and the WLAN's VLAN'swould extend out to the AP. you will also need to review the FlexConnect guides to better understand this setup as there are limitation to using FlexConnect that can hinder you from going this route. Not that simple, due to the configuration changes in the WLC and the network, but can be done.  

-Scott

[m.dridi89]

Thanks Scott,

Please can you tell me what do you mean  by  HA sku 2504 is it a license ?? or module ?? 

the HA   as i know need to be performed in same subnet so what is the difference between backup and HA?

[Scott Fella]

It is a part number for a WLC.  Backup and HA are used interchangeably.  You can review the HA N+1 guide for further reference on that. 

-Scott

[m.dridi89]

thanks Scott for your help

[m.dridi89]

hi,

 after some research  when we say ha-sku do we mean when we put the controller redundant and secondary ??

is there an active-active HA

[Scott Fella]

An HA sku is for redundancy. You would need to buy a 2504 with license if you want active active where you can put half the AP's in one controller and the other AP's on the other. HA sku is again strictly for a backup controller design. 

-Scott

[m.dridi89]

hi,

ok , but what is HA-SKU ??? is it a technology or just in an appliance 

like 2504-air-ha-sku-k9??

[Scott Fella]

It is an appliance. Part numbers can be found in the data sheet for the device:

Table 3.       Ordering Information for Cisco 2500 Series Wireless Controllers

Part Number	Description	Cisco SMARTnet® 8x5xNBD
AIR-CT2504-5-K9	2500 Series Wireless Controller for up to 5 Cisco access points	CON-SNT-CT255
AIR-CT2504-15-K9	2500 Series Wireless Controller for up to 15 Cisco access points	CON-SNT-CT2515
AIR-CT2504-25-K9	2500 Series Wireless Controller for up to 25 Cisco access points	CON-SNT-CT2525
AIR-CT2504-50-K9	2500 Series Wireless Controller for up to 50 Cisco access points	CON-SNT-CT2550
AIR-CT2504-HA-K9*	Cisco 2500 Series Wireless Controller for High Availability	CON-SNT-CT2504HA

[Scott Fella]

Here is a link to the data sheet also:

http://www.cisco.com/c/en/us/products/collateral/wireless/2500-series-wireless-controllers/data_sheet_c78-645111.html

-Scott