Connecting to a remote host via Transfer Tool results in: Connection timed out

Symptoms

The following error occurs when connecting to a remote host using the Transfer Tool:

The system stopped waiting to connect to “192.0.2.0” on port “22” after 15 seconds.
Failed to establish session and parse security token: 599 Internal Exception (Could not
connect to '192.0.2.0:2087': Connection timed out) at
/usr/local/cpanel/3rdparty/perl/530/lib/perl5/cpanel_lib/cPanel/PublicAPI.pm line 526.

Description 

This can be caused by one of the following reasons: 

•  A firewall configuration on the remote host is blocking the server
•  The SSH port that was used to connect to the remote host is incorrect.
• The source server's hostname is proxied through Cloudflare

Workaround

Check the SSH port on the remote host to ensure the port being used in Transfer Tool is corrrect by running the following command via SSH or WHM >> Terminal as root on the remote host:

sshd -T | grep '^port

Example:

[root@server ~]# sshd -T | grep '^port'
port 22

Ensure the server can reach the remote host on the remote host SSH port by running one of the following commands via SSH or WHM >> Terminal as root: (Replace $PORT with the remote host SSH port and $IP with the remote host IP address).

nc -vz $IP $PORT

telnet $IP $PORT

Examples:

[root@server ~]# nc -vz 192.0.2.0 22
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connection timed out.

[root@server ~]# telnet 192.0.2.0 22
Trying 192.0.2.0...
telnet: connect to address 192.0.2.0: Connection timed out

If nc or telnet are not installed, you can attempt to SSH to the remote host instead by running the following command via SSH or WHM >> Terminal as root: (Replace $PORT with the remote host SSH port and $IP with the remote host IP address).

ssh -p $PORT root@$IP

If the server cannot reach the remote host on the configured SSH port, ensure the firewall configuration on the remote host allows connections from the server you are using the Transfer Tool on.