How to Disable an Ubuntu Firewall

Whether you’re using Ubuntu Linux as a desktop or server, you should be taking advantage of a firewall. Why? Because the firewall is that which can help protect your machine from being hacked. It’s not a 100% solution, but it certainly makes your machine exponentially more secure.

However, there are times when that firewall gets in the way. Say, for instance, you’re finding your computer isn’t able to reach the network (or other machines cannot reach you). You’ve restarted your modem and, still, your computer cannot reach the internet or be reached via the likes of SSH. What gives? The problem could be the networking subsystem on your computer, or it could be the firewall. Either way, you need to figure out what’s wrong.

That’s just one scenario where it comes in handy to be able to disable the firewall on Ubuntu Linux.

For all the reasons you might find to disable your firewall, there’s one reason to keep you from doing so, which is the security of your machine. Once your firewall is down, your machine is open to attack. That doesn’t mean the second you drop the firewall you will be hacked. However the likelihood that it can happen increases significantly.

To that end, should you find yourself in a situation where you need to disable the firewall on your Ubuntu Linux machine, make sure it is done on a temporary basis only. What does that mean? If you must disable the firewall for a specific reason, make sure to re-enable it once you’ve finished the task at hand.

The default firewall tool on Ubuntu Linux is Uncomplicated Firewall (UFW). To find out the current state of your firewall, issue the command:

sudo ufw status

The firewall should be listed as active and will also list out any rules you’ve added.
In order to disable UFW, issue the command:

sudo ufw disable

Issue the command:

sudo ufw status

and the firewall will be listed as inactive.

At this point, run your troubleshooting (or whatever else it is you need to take care of). For example, attempt to Secure Shell into the machine with the now-disabled firewall. If you can get in (but couldn’t previously), the issue might well be that you haven’t allowed SSH connections in. To remedy that, issue the command:

sudo ufw allow ssh

Once you’ve taken care of that, re-enable UFW with the command:

sudo ufw enable

Hopefully, that solves your problems.

If you need more information about the status of UFW, you can always run the status command with the verbose switch. This command is:

sudo ufw status verbose

The verbose output will include logging level, default policies, and any rules you’ve added.

If you feel you need to completely start over with UFW, and you don’t want to go through the process of deleting all of your rules, you can always run a reset. To do this, issue the command:

sudo ufw reset

You will be prompted to okay the operation, before it will go on with the deletion of your rules. This will also have the added effect of disabling UFW. Because of this, you’ll want to re-enable UFW, after running the reset. The end result of the reset is a clean slate with which to start.