Why do we need to disable HA before we config F5?

Can you be a bit more specific on when does this happen and which BIG-IP version? I suppose it happens when the F5 box is already setup with HA functionality. Anyway, there should be no restrictions on configuring F5 with HA active as far as i know...

indeed, where did you get the idea you have disable HA before changing configuration?

Sorry I did not make it clear. Two F5 work as failover. Whenever we make some change on their configuration, we need to disable HA. and after the changing, we need to enable the HA. I think this could prevent other F5 from sync, right?

I think it is automatically sync that is why he is asking why it is needed to disable HA when changing configuration.

To boneyard

"you still don't explain who told you need to disable HA." I saw they disable HA before some engineers add new virtual server, pool, and nodes etc

"how do you disable HA?" System >>>>> High Availability >>>>> HA Group >>>>> HA Group Properties >>>>> check "Enable" box

But no matter enable HA or not, I could not find any difference between before and after the configuration change.

Maybe you are confused with disabling the HA group when you want to force one of the members to standby. See:

https://support.f5.com/kb/en-us/solutions/public/14000/500/sol14515.html