hi chan..
HA is possible with ZD1106, ZD1205 and ZD3000 controllers...
HA can be done in two ways:
Limited ZD discovery mode
- 2 controllers. controller 1 is primary and controller 2 is secondary.
there is no sync between the two controllers... when primary controller goes down, AP's move to secondary controller and will join as it is joining a new controller, may get firmware upgraded or downgraded, configuration also get changed based on how old or new configuration was on the secondary controller