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In this video you'll learn about UFW. UFW is Uncomplicated Firewall and it was developed

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to work with an intuitive syntax. It's a default that you will find on Ubuntu. Let's go to

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an Ubuntu server where I can show you how to work with it. So for this demo as you can

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see we are on an Ubuntu server. And a fun, complicating part is that I'm on SSH. So yeah,

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what are we going to do? Well, I want to check if UFW is currently available. So I'm using

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sudo ufw status. And there we can see that UFW is inactive. Well, I want to enable it.

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So sudo ufw enable. And oh boy, may disrupt existing SSH connection. Proceed with operation.

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Let's not do that. And let's do the smart thing and first use sudo ufw allow ssh. I want to make

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sure that we have a rule for SSH before I'm going to enable the firewall. And then I'm going to

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reset. And now we can see firewall is active and enabled on system startup. UFW status should show

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that at this moment. As you can see, port 22 is allowed over IPv4 as well as v6. Next, do I really

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want to sudo ufw reject out SSH? No, I don't want to do that. I want to do ufw reject out FTP. No

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FTP outgoing traffic. I'm not going to try to cut off the branch on which I'm sitting. So that is

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why I'm using FTP as I'm not using it anyway. So sudo ufw status is showing the reject out for FTP.

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And if you regret, you can always use sudo ufw delete reject out FTP. As you can see, the syntax

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is quite straightforward. But even if the syntax is straightforward, you can do pretty advanced

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things as well like sudo ufw deny proto TCP from 10.0.0.10 to any port 22. So what is that doing?

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Well, let's go back to sudo ufw status. And we can see that we have denied to port 22 for 10.0.0.10.

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So that is how you can deny one IP address or if you want to an entire network access to a specific

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port. Next, I'm going to show you sudo ufw app list because ufw can work with applications. But

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this application needs to be installed. And well, we see one only. And I can request information

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about it you using sudo ufw app info open SSH. And there we can see what it is doing its short

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description. So you can work with apps and you can work with ports. And if you want more

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information, sudo ufw logging on might be convenient that is going to enable logging so that

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you can find extensive information about firewall access, as well as blocks that might be helpful in

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troubleshooting. Finally, the man page for ufw is giving all the information about what you can do.

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Now man ufw is giving information about all the different syntax components. And based on that, you

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should be able to build yourself a pretty serious firewall.