What's wrong: -X requires a chain and a policy

user9876 · 11-13-2013, 06:28 PM

What I'm doing is wrong?

I'm trying to deploy a simple set of iptables rules directly from a howto (Ubuntu 12.04, Linux 3.5.0-39-generic, iptables 1.4.12):

Code:

#clean rules table
sudo iptables -F
sudo iptables -P INPUT DROP
sudo iptables -P FORWARD DROP
sudo iptables -P OUTPUT DROP

#allow inbound www
sudo iptables -P OUTPUT -o eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT

At this stage I get the following error:

Code:

iptables v1.4.12: -X requires a chain and a policy

What is wrong with the command and why does it mention -X whereas I didn't use it.

rknichols · 11-14-2013, 07:05 PM

The error message is mistakenly stating "-X" when it should be saying "-P". The "-P" action sets the policy for a chain and expects only the chain name and target as its two operands. For adding or inserting a new rule you should be using the "-A" or "-I" actions, respectively.

user9876 · 11-17-2013, 05:23 PM

Quote:

Originally Posted by rknichols

The error message is mistakenly stating "-X" when it should be saying "-P". The "-P" action sets the policy for a chain and expects only the chain name and target as its two operands. For adding or inserting a new rule you should be using the "-A" or "-I" actions, respectively.

Thank you, silly me! Wrongly copied stuff.. but I'm just learning.