We had a situation where we applied HF4 cumulative patch on standby and at some point both of the ltms went active/active and we had a outage.
In order to prevent this to happen again we are thinking of isolating ltm12-2 from the network and apply the patch and disable asm. SO we are thinking of disabling all the interfaces on LTM12-2 including HA interface .
Here is my steps and concerns
(1) Currently LTM12-2 is active. So we will failover to standby
(2) On ltm12-2 change the redundancy state preference to standby.
(3) Disable network interfaces on LTM12-2 and HA interface last
(4) Reactivate license on LTM12-2 to disable ASM
(5) Reboot ltm12-2
(6) Enable HA interface and than other network interfaces on LTM12-2
(7) Change the redundancy state preference to NONE on LTM12-2
our concern is with step 5 and step 6 . Will ltm12-2 become active because its trying to get a heartbeat from ltm12-1 which it won't get because after step 5 there is no connectivity in terms of HA interface to ltm12-1 .