If you on the outside looking in would that not depend on firewall rules also?
Hm, I guess. But I'm not behind a firewall and neither is the server.
On the standby what does netstat -lt show?
This is what I see on the standby
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 *:ssh *:* LISTEN
tcp6 0 0 [::]:ssh [::]:* LISTEN
tcp6 0 0 [::]:postgresql [::]:* LISTEN
What do the FATAL errors say?
I forgot their contents now, but I think they showed up for trying to connect via psql, and not as part of replication process.