Best way to change management IP?

[JVanc]

How easy is it to change the management IP to a different subnet after initial setup? I've run into a networking issue testing vReplication on vSphere where:

Internal & VM network: network A
VMware VCSA: dual-NIC on network A & B (to allow Nimble snapshot & quiescing)
iSCSI Network: network B (including management IP)

It seems that VCSA cannot find the VCSA in my DR site due to multi-NIC configuration so I want to disable the offending NIC;  this means I either fiddle with firewall rules to let the correct traffic flow from B to A, or reassign a new management IP on network A.

What's the recommended setup?

[JVanc]

On further review, shouldn't the Nimble array management IP on Network B still be able to communicate to vCenter VSCA on network A to quiesce the VMs? If so, what ports are needed?