Transfer Tool failed to connect because of an error: No route to host

Symptoms

You may see the following error message when attempting to use the Transfer Tool:

(XID strf3t) The system failed to connect to “192.0.2.0” on port “22” because of an
error: No route to host Failed to establish session and parse security token: 599
Internal Exception (Could not connect to '192.0.2.0:2087': No route to host ) at 
/usr/local/cpanel/3rdparty/perl/530/lib/perl5/cpanel_lib/cPanel/PublicAPI.pm line 526.

Description 

The "No route to host" error is generic, but it typically means that the source server cannot be reached over the given ports. This is usually caused by a firewall or a network issue.

Workaround

You can use the steps found in the following article to check if the error is due to a firewall.:

Connection refused when attempting to connect to a remote host

You may also need to ensure the ports are open in the firewall, and if you have a network firewall (particularly with a cloud server provider), you'll need to ensure the ports are open there and that the connection isn't being blocked on the network.

You may also want to review the following article:

How to Troubleshoot Network Issues

If you've done all of this and are still seeing this issue, you'll want to reach out to your data center, ISP, or hosting provider to see why the servers aren't able to reach each other.