Linux – How to allow outgoing connections via iptables

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I have two servers. The program on the first needs to communicate with the second on port 2194.

I know its not working, because when I do:

root@server1 [~]# telnet myserver2.com 2194
Trying 123.123.123.98...
telnet: connect to address 123.123.123.98: Connection timed out
telnet: Unable to connect to remote host: Connection timed out

server1# iptables -L -n

Chain INPUT (policy DROP)
...
...

Chain FORWARD (policy DROP)
target     prot opt source               destination

Chain OUTPUT (policy DROP)
...

Chain LOCALINPUT (1 references)
target     prot opt source               destination
...

Chain LOCALOUTPUT (1 references)
target     prot opt source               destination
...

Chain LOGDROPIN (1 references)
target     prot opt source               destination
DROP       all  --  0.0.0.0/0            0.0.0.0/0

Chain LOGDROPOUT (1 references)
target     prot opt source               destination
DROP       all  --  0.0.0.0/0            0.0.0.0/0

Best Answer

To allow outgoing connections from server1 to server2 on TCP port 2194, use this on server1:

iptables -A OUTPUT -p tcp -d <server2ip> --dport 2194 -j ACCEPT

To allow incoming connections from server1 to server2 on TCP port 2194, use this on server2:

iptables -A INPUT -p tcp -s <server1ip> --dport 2194 -j ACCEPT
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