iptables blocking all ports except port 80

iptables blocking all ports except port 80

[Ivan Matala]

I have iptables in centos 5.5.

How can i only allow port 80 in my vps.. Because i have squid in
remote server and my vps connects to port 3128 there. but when i do
torrent, it works,, how can i disable it? Please give me steps in
iptables routing thanks.

In short, what rules to add to block other ports except, ssh and port 80, 3128.
Thanks very much.

Re: iptables blocking all ports except port 80

[Andrew Beverley]

On Tue, 2011-06-14 at 07:41 -0700, Ivan Matala wrote:
> In short, what rules to add to block other ports except, ssh and port 80, 3128.

Assuming you're using iptables to forward packets, something like:

iptables -A FORWARD -p tcp -m multiport --dports 22,80,3128 -j ACCEPT
iptables -A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -j DROP

Your email is not very clear, so it depends whether you are trying to
allow inbound connections or connections to external servers. You'll
therefore need to change dports to sports as required. In the same vein
you may also need to change FORWARD to INPUT.

Andy