iptables configuration not working

Question

I have a VPS for Apples push notification service I am trying to open a port 2195. I am currently doing this

vi /etc/sysconfig/iptables

then I go to insert mode of vi and enter these two lines

-A -I INPUT -p tcp --dport 2195 -j ACCEPT
-A -I OUTPUT -p tcp --dport 2195 -j ACCEPT

then I save the file and quit vi.

Then I restart iptables service by

service iptables restart.

But after that when I try to telnet by doing

 telnet localhost 2195

I get this

Trying 127.0.0.1... telnet: connect to address 127.0.0.1: Connection refused

Any pointers....?

Server is red hat on hostgator

Answer 1

Your rules are bad. You can't use -A and -I together, -A means append as last rule, -I menas insert as first rule.

Answer 2

Two things I notice immediately:

1. You have allowed packets out with a destination port of 2195 but if someone contacts your server on 2195 then your return packets will have a source port of 2195. Depending on what traffic is needed, you can either change the --dport in the OUTPUT chain to --sport or add two extra rules with --sport as well.
2. A connection refused error implies different things about what has happened to the connection than a timeout would. It suggests that your service is not listening on port 2195. Could you run netstat -tan | grep LISTEN and check that your service is listening on port 2195 on the loopback interface?

Answer 3

Please first validate your rules are applied or not via

sudo iptables -L -vnx

If the rules is there, make sure the service which listens on 2195 is running or not.

sudo netstat -tulpn