 This video is part of a series. Be sure to check out the link in the description to the full playlist and Today we're going to look at a simple command that will allow you to block IP addresses both incoming and outgoing on your system using the ARP command. So what I'm going to do here is To show you I can ping 192.168.1 dot 102 which is my cell phone and I can ping it right now And if there are any services running on it I could access them such as web servers and whatnot, but I can use sudo or be root to use ARP dash S and then give it an IP address in this case 192.168.102 And I can say on device zero and I'll hit enter and that is now blocked I can now hit enter and you can see that I cannot access I cannot ping that device, but it works the other way as well I'm going to try to show you this on my cell phone here So here's my cell phone you can see I've already Connected to the web server running on my desktop here, but if I click to refresh It's not going to load because This device is being blocked. So we're blocking it in two ways We can't get to this IP address and this IP address is blocked from accessing us so that's Just showing you that it's not going to load you can see the little blue bar at the top right there Waiting trying to connect trying to connect and it's it's it's it's just not doing it So and we still can't ping it over here Control C to kill that if we want to unblock we can use the ARP command again again as sudo is root or root Dash D and then the IP address that we want to unblock 102 and we'll hit enter and now I can ping that device There we go took a second. I'm able to ping it and I should be able to load up on On the screen as well there. Let me try this machine SSH into 192.168.1 dot 111 And you can see that it prompts me type in a password to connect to that machine That's just a raspberry pi sitting on my desk behind me. I'll control C to get out of that But if I was to use ARP dash s to block 192.168.1 dot 111 Oh, and then give it a hardware in this case zero for my first hardware device I can now try to SSH in that and I'm not going to be able to connect and it will work the other way around if they try to SSH in or connect to my web server or any other service I have running. They are not going to be able to so That's it and again to undo that sudo ARP dash D and the IP address that you want to remove from your block list And now I should be able to try to connect to that. So that's it I hope you found this useful in case you need to block some IP addresses both in going and outgoing I thank you for watching if you enjoyed this video think about becoming a supporter over at patreon.com forward slash melex 1,000 there should be a link in the description of this video even a dollar a month is Very appreciated If you can't support me financially think about liking sharing subscribing and commenting on this video If you know of other ways of blocking IP addresses, there are other ways And other options for the ARPs Program, let me know in the comments below. Please visit my website films by chris.com That's Chris the K and as always I hope that you have a great day Be sure to check out the full playlist in the description of the video