You can configure the source IP from which the mirror is send.configure mirror <mirror name> from <tab>auto-source-ip Automatically use source IP address of egress VLAN used to reach remote IP (Default)<source_ip_address> Use specified local IPv4 add...
I could not find a log so checking process could be a method.However, if the migration takes that long, if possible it would be good to reduce retention time for end system events and after the DB decreased enough try again ?You can rerun the migrate...
hint, ipforwarding should be enabled on each vlan, not just on internetten. And what about NAT ? Does the internet router knows these IP's ? Routing needs to be working both ways.