One thing that bothers me a lot when using ssh with VMs in my homelab is that I re-use IPs after destroying/recreating VMs. My
.ssh/known_hosts then grows and contains a lot of obsolete entries, and eventually, it ends up conflicting.
Here the trick to disable strict host checking on connect for a subset of IPs. Just add the following in
$ cat ~/.ssh/config ... Host 10.2.1.* StrictHostKeyChecking no UserKnownHostsFile=/dev/null ...
Another possiblity is to remove them. Simply use
$ ssh-keygen -R "10.2.1.22" # Host 10.2.1.22 found: line 40 # Host 10.2.1.22 found: line 41 # Host 10.2.1.22 found: line 42 /home/mycroft/.ssh/known_hosts updated. Original contents retained as /home/mycroft/.ssh/known_hosts.old