Allow ssh incoming/outgoing and blocking all outgoing besides specific ports

Question

I am trying to create iptable rules that will allow incoming and outgoing ssh connections, and then allow outbound connections to specific ports, then finally drop anything that doesnt match.

These are the rules I have come up with, the SSH rules work, but when I tunnel into the box I cant seem to access http (port 80) even though i've allowed it. Can anyone spot the mistake?

#!/bin/bash
#clear iptables
iptables -F
iptables -X

#set default policy to drop
iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

#accept everything no matter port on localhost
iptables -A INPUT -i lo -j ACCEPT

#allow established connections
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

#allow input on port 22, (established connections auto accepted)
iptables -A INPUT -p tcp --dport 22 -j ACCEPT

#allow traffic going to specific outbound ports
iptables -A OUTPUT -p tcp --dport 80 -j ACCEPT
iptables -A OUTPUT -p tcp --dport 443 -j ACCEPT
iptables -A OUTPUT -p tcp --dport 6667 -j ACCEPT
iptables -A OUTPUT -p tcp --dport 6697 -j ACCEPT
#...

#drop anything that doesnt match the rules above
iptables -A INPUT -j DROP
iptables -A OUTPUT -j DROP

Thanks for your time.

Answer 1

You might want to add the DNS ports, otherwise you may not be able to resolve any hostnames.

Allowing OUTPUT for TCP and UDP Port 53 should help.