What version of software you are running on your WLC ? 7.0.x 7.4.x or 7.6.x Recently Cisco published this document (Cisco DOC 40178) stating they are going to deffer (ie no longer support available or you cannot download those software versions anymore)
So all releases made prior to Dec 2013 going to be deffer. Here is the bug CSCul68057 details which cause this. WLC will go unexpected reloads due to this
Effectively now you have 3 choices. Even though 220.127.116.11 is listed in the above, due to some critical bugs of that version Cisco is working on releasing 7.6MR1 in coming weeks, so you should not run 18.104.22.168 code unless you want to experience those issues 😯 .
Also it is mentioned “for complete fix, upgrade to FUS (Field Upgrade Software) 22.214.171.124 as well“. It is very important to make sure you adhere to this. Here is the release notes for this.
So What is the best option ? Depend on what version you are running today, you can determine where to go. My preferred choice would be 7.4MR2. But if you are already running 802.11ac (3700AP or 3600 with ac module) then 7.6MR1. If you are still with 4400/WiSM1/2106 then 7.0MR5.
Cisco also recommending 7.4MR2 as that code went through “AssureWave” program & tested thoroughly (see the blue star below). Also you can refer this report for what features tested by Cisco under AssureWave program for 126.96.36.199 code.
Update @ 5th March 2014.
Noticed this vulnerability notice on Cisco WLCs published today. I think that is the main reason for the above software code deferrals. Here is the summary of it & as you can see it leads to the 3 software codes listed in the above
If you are using IOS-XE products (5760/3850/3650) then those are not impacted by this vulnerability 🙂