The replication job progresses to the ‘replicating virtual machine’ stage then hangs for a few minutes before failing with the above error message.
This error is an indication that vRanger is unable to establish an SSH connection between the two ESX hosts involved in the replication.
Check to make sure that the necessary firewall ports are open on the ESX hosts to permit bi-directional communication on TCP port 22 by connecting to the host with the Virtual Infrastructure Client. Click the “Configuration” tab, then select “Security Profile” in the “Software” box. Click the “Properties” link in the upper right corner of the page. Check to see that both the “SSH Server” and “SSH Client” check boxes are checked and also check the status of the SSH daemon, it should be “Running”. Once this is done connect to the source ESX host with putty and try to ping the target host. If this is successful try to establish an SSH connection with SSH <server FQDN>. Now connect to the target ESX host and repeat the same process, first pinging the source host and then establishing an SSH connection.