How to change the domain name on a ACM pair of server without service interruption

[badozc]

Hello Dear community

I have to change all Domain Name and DNS primary and Secondary parameters for all my LSPs and my Main ACM server pair running ACM 6.0.1. I did already all LSPs for one cluster but I face an issue when doing so on the Main ACM server pair. I face the issue when I change the parameters on the standby server after it restart as the alias Processor Ethernet IP address is not reacheable from the remote media gateways that invoke a registration onto the LSPs. I had limited impact as only 4 MG are using the PE in the MGC list. Other MG use clan1, clan2, clan3, LSP in the MGC list and did not lose the connectivity with central hub.
The root cause seems to be that as the 2 servers are not anymore in the same domain they do not see each other properly and appears to be both active at the same time therfore preventing the alias PE IP address to respond with the active server.

How to prevent this and what would be the method / sequence to change both servers Domain Name with minimal impact ?

Any suggestion, recommendations are welcome.

Regards
Christophe