More info should be provided on the `ProxyJump` option of SSH with relation to the lab setup.
For users who extensively use the SSH agent and have many different SSH keys the provided ssh command under "SSH Private Key & Instructions" produces an obtuse error:
ssh -i rht_classroom.rsa -J cloud-user@148.62.94.208:22022 student@workstation
cloud-user@148.62.94.208: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
Connection closed by UNKNOWN port 65535
This is because the connection needs an interactive shell to accept the host key, but because there are *two* SSH commands being run, the inner ProxyCommand is attempting to send all of the keys for the local SSH configuration first *before* sending the manually specified key. This then hits the limit on the number of keys which can be checked and fails.
I was able to work around this by specifying the following command:
ssh -o IdentitiesOnly=yes -i rht_classroom.rsa -o ProxyCommand="ssh -o IdentitiesOnly=yes -i rht_classroom.rsa -W %h:%p cloud-user@148.62.94.208 -p 22022" student@workstation
This allows me to correctly acknowledge the host key before proceeding by narrowing the scope of keys sent in both SSH commands.
