The link will explain a lot, but one thing to make sure also is that your configuration between the two WLC's are similar except for host name and up address. You will also configure the ap with the primary wlc and secondary wlc info. This way the ap knows which wlc it belongs to and which wlc it needs to go to if the primary is unavailable.
As long as the code is the same, there is no downloading. This is how you want it. Now if wlc1 comes back online, enabling ap fallback will allow the AP's to go back to wlc1 if it is configured for wlc1. Make sure master controller is disabled.
Transferring Crash file from standby: Login to the Active WLC in HA.
From CLI: (Cisco Controller) >transfer upload datatype crash (Cisco
Controller) >transfer upload filename (Cisco
Controller) >transfer upload mode tftp (Cisco Controller) >transfer
This is the start of a display filter cross reference between Wireshark
and OmniPeek. The 1st installment is a table of advanced filters. More
filters will be added as time allows. It is a living doc, so check back
for changes every so often Please feel f...
I have created a Powershell script to automatically add a Wireless Guest
User on Cisco WLCs. (tested on 2500 Series) The script should be
completely self explanatory. Prerequisites: Powershell SNMP Module
(Install-Module -Name SNMP) SNMP Write Access to y...