Best HA Solution Option for WLC 2504 running 7.0.220.0

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Hey Wireless Team Members!

I have a quick question on what is the best option for setting up some form of HA for a small setup I am running into.  Before we even proceed further - I KNOW the code is soooo old!  But that is not an option due to the situation at the present moment. So no upgrades can be done or modifications to existing WiFi Setup!  The company is completely aware of the non-synchronization and overall administrative overhead this is going to take to manage.

The existing setup is that of a single WLC 2504 running 7.0.220.0 and supporting less than 6 Access Points.  I am unsure if the AP's are setup in Local or H-REAP mode, but for the moment I am going to assume H-REAP; I will know sooner than later.

The company is purchasing an additional WLC 2504, which will act as a Secondary WLC.  The purpose of this Secondary WLC is solely meant for immediate replacement/swap for the Primary WLC in the event the Primary a major malfunction, crash, or problem.

So with that being said, I figured my only real options are as followed.
But please, correct me if I am wrong!

Option#1 - Just setup and configure the Secondary WLC to replicate everything in the existing Primary today.  Once the current running configurations are loaded onto the Secondary WLC, put it aside (not physically connected to the network) and if the day ever comes where it will need to be used - just take out the Primary and rack/cable up the Secondary.  In this case, I am assuming the Secondary WLC would configured identically to that of the Primary, correct?  Meaning same interfaces, same IP Addressees, same hostname, and etc. 

Option#2 - Setup and configure the Secondary WLC as a "Backup Controller".  Have this racked and cabled permanently on the network. This way if there is ever an issue with the Primary WLC, failover to the Secondary WLC will be automatic (in the sense) and not contain any downtime for the physical setup portion of the Secondary WLC.

This seems like the preferred setup to me. My only question is, how would the Secondary WLC be configured for its role as the replacement?
Unlike Option#1 above, would all of the configurations need to be different than that of the Primary WLC?
Meaning the interface (MGMT/Dynamic) configurations on this type of setup require different IP Addresses, different hostnames, and etc?
What configurations would need to be different from that of the Primary WLC in going with Option#2?

With all this being said, please respond accordingly and/or let me know of any recommends the Wireless Experts out there may have!  As always, your help is greatly appreciated and I will certainly use the rating system!  

[Ric Beeching]

I was going to write  a spiel but see Scott's post here:

https://supportforums.cisco.com/discussion/12160596/how-can-i-configure-wlc-2504-do-ha-n1-method

Quote:

"With the 2504, the method of deploying an HA sku using N+1, is the same as if you had two licensed WLC's.  Configure both WLC's and just make sure the hostname and ip address used for management and the dynamic interfaces are different.  The VIP should be the same along with the mobility group, rf group, etc.  The main thing is to define the WLC's as the primary and secondary on the AP itself.  If you click on the AP, there is a tab called High Availability.  In that tab, you enter the hostname of the WLC, this is case sensitive, and the ip address of the WLC.  That is all you need to do.

For failover to happen, make sure you have Fallback enabled on the main screen in the Controller tab of both WLC's.

Here is a link to that:

http://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/69639-wlc-failover.html

The HA Guide for N+1 is the same for all WLC's that support HA.  The only difference between the 2504 and the higher end models is that there is no service port, and of course the backplane and other higher end stuff:)

Please rate helpful post and Cisco Support Community will donate to Kiva

Scotty"

[Ric Beeching]

In fact Sandeep has written a whole blog post on it:

https://rscciew.wordpress.com/2014/06/07/n1-high-availability-configuration-on-cisco-2504wlc/

[mohanak]

Refer the link : https://supportforums.cisco.com/discussion/11874876/does-wlc-2504-supports-ha-or-not