I use an alias to select when to, and not to, use host keys; alias ssht='ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no' ssht floaty.vm # doe

I use an alias to select when to, and not to, use host keys; alias ssht='ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no' ssht floaty.vm # does not use host key checking ssh my.bastion.host # validates host key Really I ought to get SSHFP records populated when my vm's are created...