I am currently migrating from 8.1.3 7-mode to 9.5P12 without using 7MTT tool. All the configuration was fine until i try to initialize the snapmirror relationship. It shows error could not connect to source host.
Network was fine, no firewall issue as both old and new system are at the same VLAN.
I am not sure what is going on. Was it compatibility issue ?
Some other things to check is on cdot check your cluster/svm peering to the old 7mode system. Also in 7mode systems sometimes if you have multiple interfaces snapmirror traffic may go out the wrong interface vs the host name.