postgresql (remote) connection refused - postgresql

Question

My error:
# psql -U postgres -h 10.230.5.51
psql: could not connect to server: Connection refused
Is the server running on host "10.230.5.51" and accepting
TCP/IP connections on port 5432?
in postgresql.conf:
listen_addresses = '*'
port = 5432 # (change requires restart)
I have added the client server in pg_hba.conf (username/database replaced by X)
host X X 10.230.5.21 md5
host X X 10.230.5.22 md5
Before I added those in the pg_hba.conf, it gave me this error:
# psql -U postgres -h 10.230.5.51
psql: FATAL: no pg_hba.conf entry for host "10.230.5.22", user "X", database "X", SSL on
FATAL: no pg_hba.conf entry for host "10.230.5.22", user "X", database "X", SSL off
So I assume the first steps I have taken are correct?
The last step I feel like I may be missing, could be iptables. they look like this:
-A INPUT -i lo -j ACCEPT
-A INPUT -d 127.0.0.0/8 ! -i lo -j REJECT --reject-with icmp-port-unreachable
-A INPUT -s 10.230.4.0/22 -j LOCAL
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 8010 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 10443 -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -p gre -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-port-unreachable
-A LOCAL -p udp -m state --state NEW -m udp --dport 53 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 53 -j ACCEPT
-A LOCAL -p udp -m state --state NEW -m udp --dport 123 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 2181 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 2888 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 3888 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 5432 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 7000 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 7001 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 9042 -j ACCEPT
-A LOCAL -p tcp -m state --state NEW -m tcp --dport 9160 -j ACCEPT
Is the iptables ok? I can see that port 5432 is on the list. Is the connection being refused by another rule before that? iptable commands are weird.
General information:
Both computers are running linux. I did not originally setup the database. The database is running fine, but only locally, even though this happened when running the command on the server with postgres database:
# psql -U postgres -h localhost
psql: could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?

Answer 1

I faced the same problem in PostgreSQL 9.6 and I resolved in the following way.
sudo nano /etc/postgresql/9.6/main/postgresql.conf
put '*' instead of localhost on the following line and removed comment sign(#)
listen_addresses = '*'
Add the following line in pg_hba.conf
#TYPE DATABASE USER CIDR-ADDRESS METHOD
host all all 0.0.0.0/0 md5
Restart the service:
(Ubuntu) sudo service postgresql restart

Answer 2

Do following
Update : /var/lib/pgsql/<version>/data/postgresql.conf
change : #listen_addresses = 'localhost' to listen_addresses = '*'
restart service

Answer 3

Check if you did not switch DATABASE with USERNAME.
This also happened to me and this fixed it. The correct syntax is:
host DATABASE USERNAME ADDRESS METHOD