BigIP LTM Pool Monitors Stuck on "Checking"
We have dissolved an F5 BigIP HA pair to redesign/update the configurations of a system without any downtime, the plan is to run two BigIp's side by side, and once we're happy with the new build, we'll cut over and re-enact HA with the new build.
The issue is with restarting the BigIP with the new configuration, in that about half of the monitors stay in the checking state. If we remove the monitors from a pool and re-add them, the monitors come up and the pool members come back online. The monitors that don't come up appear to be random, and include many different types such tcp-half-open, HTTP, complex HTTP, and even DNS monitors (trying to avoid ICMP).
The nodes that are being monitored can even be the same, for example one of the monitors that is stuck at the moment is for and Exchange OWA check, whereas the same node being monitored by an RPC check is up.
This is 11.5 HF2. The ltm log doesn't seem to contain much information apart from "monitor status up" when the monitors come back online after being manually removed/re-added to a pool.
It's as if there are too many monitors for the system to bring up post reboot, and that doesn't fill me with warm feelings.
Any help would be appreciated!