Hi Tim,
Sebastien, I run a relay on a machine that has an internal private IP, behind a NAT router with a public IP.
In my experience, I need to specify the NAT router's public IP in the torrc, otherwise tor doesn't include it in the router descriptor it submits to the consensus.
This shouldn't happen typically, Tor tries to learn its IP address by looking at the traffic it receives.
If that process isn't working for me, is this a bug I should report?
Likely. Can you try again, noting the kind of log messages Tor might emit?
Cheers Sebastian