Discovering which interface a host is using

Hey guys - Just started a new position at a large enterprise. They immediately hit me with decomming an NS-960 (2 DM's 1 standby) Unified frame. So I'm doing host based NFS migrations via management AIX server to a VNX7500 with 6DM's and 1 standby. I do not have access to the actual Unix/Linux servers that use the NFS exports. The network has been setup on the VNX with interfaces on the same subnets as the interfaces on the 960.

The issue I'm facing is: the interfaces are now spread out through more data movers and I need to put the new (target) VNX filesystems on the data movers who's interfaces match that of the 960's.

My question is: how do I tell which interface a host is using when multiple are configured for 1 data mover? Emails are often not replied to when trying to find out from the Unix admins.