Yes, high availability.
I can't recall the commands for that, it's been like 7-8 years since I last used an MCS, you can use the ? in CLI mode to get the different commands and try to find the right one as that command no longer exists in recent releases of CUCM as HA is now handled via ESXi.
As mentioned, as your NIC is already down, I'm not even sure if the config will work or not, it should have worked if it had been configured prior to the failure.
if this helps, please rate