Troubleshooting

Connection

XXX is not in your SSH known_hosts file

This is because the version of SSH shipped with ROS cannot understand the ~/.ssh/known_hosts generated by the latest SSH. Assuming the Q.bo's IP address is 129.169.154.82, firstly remove the existing entry:

$ ssh-keygen -f "/home/rjw57/.ssh/known_hosts" -R 129.169.154.82

Then log in again forcing the use of the RSA algorithm:

$ ssh -oHostKeyAlgorithms='ssh-rsa' 129.169.154.82

See a related ROS forum answer.