[tor-relays] "Your server (xxxx:443) has not managed to confirm that its ORPort is reachable."

[Pham Minh Duc]

I see this in syslog:

Your server (xxxx:443) has not managed to confirm that its ORPort is
reachable. Relays do not publish descriptors until their ORPort and
DirPort are reachable. Please check your firewalls, ports, address,
/etc/hosts file, etc.

torrc:

Nickname Contake
ORPort 443
ExitRelay 0
SocksPort 0
ControlSocket 0
ContactInfo contakechuyennghicmt at gmail.com

What happened and how to fix this?