If you have a stable network (AP70s do not reboot), this is what I would do:
- Provision a second controller on 6.4.3.1 on a with the same configuration as the first, but with a different management IP address.
- Turn of ADP discovery on the old controller so that no new access points will find it:
config t
adp discovery disable
adp igmp-join disable
- When you boot up new AP205s in place of an AP70, it will only find the new controller
- Your AP70s, as long as they do not reboot, will continue to function
Gotchas
- If an AP70 reboots, it will find the new controller and cease to function, so there is some risk
- If you are doing any type of authentication on your controllers, when a user roams from one controller to the next, they will be forced to reauthenticate
Strategy
- If you simply make the wireless network open during the transition, roaming should be seamless and just work. You can always turn authentication back on, when you are finished.
Please let me know if you have any questions about this.