Setting up my first #freebsd jail. Good news is it seems to be working. Bad news is I spent a bunch of time futzing around with networking before trying - https://iocage.readthedocs.io/en/latest/networking.html
Apparently it isn't auto-creating the bridge.
Also a bit surprised it starts the jail with the create command, before I've had a chance to mount the extra files and configure sshd.
A Mastodon instance for info/cyber security-minded people.