LinuxQuestions.org - newb question about iptables

Quote:

Originally Posted by ripper

Chain INPUT (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination

i deleted all rules
now ho do i start from the begining :|

First off, I recommend creating a script that populates iptables, rather than attempting to modify the tables directly. This way you can modify as needed, and run the script to update.

My script starts out like this:

Code:

iptables -P INPUT DROP

iptables -P OUTPUT DROP

iptables -F INPUT

iptables -F OUTPUT



iptables -A INPUT -j ACCEPT -m state --state ESTABLISHED,RELATED

iptables -A OUTPUT -j ACCEPT -m state --state ESTABLISHED,RELATED



iptables -A INPUT -j ACCEPT -p all -s localhost -d localhost

iptables -A OUTPUT -j ACCEPT -p all -s localhost -d localhost



iptables -A INPUT -j ACCEPT -p all --dport ssh

iptables -A INPUT -j ACCEPT -p all --dport http

iptables -A INPUT -j ACCEPT -p all --dport ftp

1st section: sets the default behavior to DROP, clears the current tables
2nd section: allows all established connections to go through
3rd section: allows local machine processes to talk to each other.
This is very important.
4th section: is where you can specifically allow connections via port.

This is not nearly all my script, but it should get you started. Don't place your script in the rc.local until you're sure it will work. You can just restart your box to regain access. Otherwise if you make a booboo you might not be able to access your system.