Is port 5432 open for postgres?

Question

Here is the output of the netstat command on ubuntu 14.04 server:

admin@ibm-testbox:~$ netstat -tulnp | grep 5432
(No info could be read for "-p": geteuid()=1000 but you should be root.)
tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN      -

It seems that the port 5432 is listening to tcp traffic on loopback. The server ibm-testbox is behind a firewall and port forwarding is used to route the public traffic to the server. But we still can not make connection to the postgres server:

PG::ConnectionBad (could not connect to server: Connection refused (0x0000274D/10061)

Is the port 5432 open?

Answer 1

You have to check the listening address. As you can see it is only listening on that port via the localhost IP (127.0.0.1:5432).

The port is not open for external connections, which is the default setup and the most secure for most cases.