How to make sure that firewall is off?

I'm new to Ubuntu. I want to turn off firewall and make sure that it's turned off and want to turn off iptables.

iptables:
  Installed: 1.4.21-1ubuntu1
  Candidate: 1.4.21-1ubuntu1
  Version table:
 *** 1.4.21-1ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status


Chain INPUT (policy ACCEPT)
target     prot opt source               destination         

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destinat

Solution 1:

sudo ufw status
Status: inactive

You can turn it off and on with ...

sudo ufw disable
sudo ufw enable

By default it is disabled.

You can check if there are iptables rules active with:

sudo iptables -L

Your output, with no lines between the target prot opt source destination header and the next Chain, indicates that no rules are active.

If you have iptables active this will cancel it

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

• explanation of all the options

If you want a graphical method:

sudo apt-get install gufw

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