HowTo Disable The Iptables Firewall in Linux

Posted on in Categories , , , , , , last updated June 28, 2012

I need to disable firewall in Linux for testing purpose. I’m using CentOS and RHEL version 4.4 / 5 / 6. How do I disable the firewall in Linux?

A Linux firewall is software based firewall that provides protection between your server (workstation) and damaging content on the Internet or network. It will try to guard your computer against both malicious users and software such as viruses/worms.

Task: Disable / Turn off Linux Firewall (Red hat/CentOS/Fedora Core)

Type the following two commands (you must login as the root user):
# /etc/init.d/iptables save
# /etc/init.d/iptables stop

Turn off firewall on boot:
# chkconfig iptables off

Task: Enable / Turn on Linux Firewall (Red hat/CentOS/Fedora Core)

Type the following command to turn on iptables firewall:
# /etc/init.d/iptables start
Turn on firewall on boot:
# chkconfig iptables on

Check out related media

See firewall start and stop video tutorial:

A note about other Linux distribution

If you are using other Linux distribution such as Debian / Ubuntu / Suse / Slakcware Linux etc., try the following generic procedure. First, save the current firewall rules, type:
# iptables-save > /root/firewall.rules
OR
$ sudo iptables-save > /root/firewall.rules
Next, type the following commands (login as the root) as bash prompt:

iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT

Or create a shell script as follows and run it to disable the firewall:

#!/bin/bash
# reset.fw - Reset firewall
# set x to 0 - No reset
# set x to 1 - Reset firewall
# ---------------------------------------------------------------------------------------------------------------
# Added support for IPV6 Firewall
# ---------------------------------------------------------------------------------------------------------------
# Written by Vivek Gite <[email protected]>
# ---------------------------------------------------------------------------------------------------------------
# You can copy / paste / redistribute this script under GPL version 2.0 or above
# =============================================================
x=1
 
# set to true if it is CentOS / RHEL / Fedora box
RHEL=false
 
### no need to edit below  ###
IPT=/sbin/iptables
IPT6=/sbin/ip6tables
 
if [ "$x" == "1" ];
then
	if [ "$RHEL" == "true" ];
	then
	      # reset firewall using redhat script
		/etc/init.d/iptables stop
		/etc/init.d/ip6tables stop
	else
		# for all other Linux distro use following rules to reset firewall
		### reset ipv4 iptales ###
		$IPT -F
		$IPT -X
		$IPT -Z
		for table in $(</proc/net/ip_tables_names)
		do
			$IPT -t $table -F
			$IPT -t $table -X
			$IPT -t $table -Z
		done
		$IPT -P INPUT ACCEPT
		$IPT -P OUTPUT ACCEPT
		$IPT -P FORWARD ACCEPT
		### reset ipv6 iptales ###
		$IPT6 -F
		$IPT6 -X
		$IPT6 -Z
		for table in $(</proc/net/ip6_tables_names)
		do
			$IPT6 -t $table -F
			$IPT6 -t $table -X
			$IPT6 -t $table -Z
		done
		$IPT6 -P INPUT ACCEPT
		$IPT6 -P OUTPUT ACCEPT
		$IPT6 -P FORWARD ACCEPT
	fi
else
        :
fi

To restore or turn on firewall type the following command:
# iptables-restore < /root/firewall.rules

GUI tools

If you are using GUI desktop firewall tools such as 'firestarter', use the same tool to stop the firewall. Visit:
System > Administration > firestarter > Click on Stop Firewall button:
Sample outputs:
Howto disable the iptables firewall in Debian / Ubuntu Linux

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

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28 comment

  6. on fedora, once you enabled firwalls/selinux during installation, I can never make nfs boot or ftp works. you can see firewall disabled, iptables disabled, yet no help. Either selinux or fedora GUI has bugs, what I get:
    Loading: TFTP error 2: Only absolute filenames allowed
    Failed.
    to our people, the selinux is a nightmare. forget what the system told you. selinux adds extension to file attributes then some garbage cannot be removed.

    Reply Report comment

  7. Hi – first time here and really need some help!

    I gave my father in law a netbook for Xmas with Linux as an operating system but cannot connect to Sky broadband. Sky unable to help, any ideas??

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  14. how can we stop the iptables service in ubuntu???
    i have tried “services iptables stop” but it is giving “unrecognized service”.
    is there any other command or method to do so???

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  15. HI,
    I am very confused about iptables status.

    I stopped my iptables by running ” service iptables stop”, later on i checked wheter it is really running or not by running “service iptables status”. It shows me ” Firewall is disabled”. If I run iptables -L it shows me the list of INPUT/OUTPUT/FORWARD Chains. If again i will run ” service iptables status” it will show me againall chains. What it really means, does iptables start auutomatically when I type ” iptables -L”? Please reply lots of confusion!!!

    Thanks in advance.

    Vijay

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  18. Debian Stable doesn’t seem to have an init.d script, or the services application, or the chkconfig application. How does one start/stop/restart the iptables service on Debian?

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  23. For ubuntu/debian servers, it is better to run default policy change, “iptables -P INPUT ACCEPT” before “iptables -F”, otherwise you will lose current connections immediately if your default policy was set to DENY

    iptables -P INPUT ACCEPT
    iptables -P OUTPUT ACCEPT
    iptables -P FORWARD ACCEPT

    iptables -F
    iptables -X
    iptables -t nat -F
    iptables -t nat -X
    iptables -t mangle -F
    iptables -t mangle -X

    This should be applied to the script file too.

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