Upgrading Two Controllers in Availability Mode

This section, which describes how to upgrade the software version on two controllers in availability mode, is applicable if the availability pair is made of one of the following combinations:

Availability Pairs

Controller 1	Controller 2
C25	C25
C35	C35
C4110	C4110
C5110	C5110
C5210	C5210
V2110	V2110

Note

The two wireless controllers in an ‘availability‘ pair must be running the identical version of the software.

For the ease of understanding, this section is explained with the help of the following hypothetical scenario:

• The upgrade is to be carried out on the two controllers — EWC-1 and EWC-2.
• Both the controllers are operating in ‘availability‘ mode.
• Both controllers are running the previous software release, and they need to be upgraded to the next software release.
• Each controller has two APs. EWC-1 has AP-1 and AP2, whereas EWC-2 has AP-3 and AP-4.
• AP-1 and AP-2 are configured as ‘Local‘ on EWC-1 and ‘Foreign‘ on EWC-2.
• AP-3 and AP-4 are configured as ‘Local‘ on EWC-2 and ‘Foreign‘ on EWC-1.

The following figure depicts the hypothetical upgrade process:

The Upgrade Process for Two Controllers in Availability Mode