they're an ASA pair, the on-device hostname/sysName is always sync'd to be same same

dns for the m0's can be (is) unique/different.

wrapper logic on the addhost check to allow dup sysName if box (via e.g. sysDescr or sysObjectID) is ASA?

dunno.

R.

Sent from my iPhone

you have obviously same hostname on devices.

what show these commands: # sh run | i hostname # sh run | i domain-name

-- Mike Stupalov