My notes, things I have learned, and documentation I have created.

To have sshd listen on a different port on two interfaces, you can configure the /etc/ssh/sshd_config like so:

vi /etc/ssh/sshd_config
…
ListenAddress 10.10.10.10:22
ListenAddress 11.11.11.11:6666
…

This will have sshd listening on port 22 on the interface configured with IP address 10.10.10.10 and port 6666 on the interface configured with IP address 11.11.11.11.

Restart sshd:

systemctl restart sshd