How to block Internet access for a specific Linux user using iptables.
Block Internet access for a specific user or user group on Linux. This works very well using iptables. A potentially very useful Linux tip.
iptables
Blocking websites with iptables can be done, this will be useful on a gateway.
Blocking unwanted websites with iptables can be done. This is not done via an Internet Protocol address, as this does not work. But matching strings does work. I have found out a way to do this. This sample below shows a few rules to block a website, if you try and load it, it will … Read more
Iptables config for mapping an OpenVPN IP address to a physical machine address.
This iptables config will map the 10.8.0.0 IP address to the 54.66.223.254 IP address range to enable the OpenVPN deamon to function. This is what I used when I was using OpenVPN to connect securely to a remote Amazon instance for access to a Linux virtual machine. # Generated by iptables-save v1.4.21 on Sun Feb … Read more
Iptables samples. Very good ways to filter network traffic.
Sample Iptables configurations A sample iptables output that I am using on an OpenVPN server to allow Internet traffic to be passed through it. ubuntu ~ $ sudo iptables-save # Generated by iptables-save v1.4.21 on Wed Aug 2 22:19:48 2017 *filter :INPUT ACCEPT [2654934:1228315333] :FORWARD ACCEPT [31023:17433690] :OUTPUT ACCEPT [2475842:555885003] COMMIT # Completed on Wed … Read more
Use the iptables firewall to block ads on your Linux machine.
How to block ads using rules in iptables on Linux.
How to have iptables entries applied on boot.
The iptables entries are lost upon reboot with a standard configuration, but this can be applied on boot with the right script. Create a script in the /etc/network/if-up.d directory named iptables. jason@hoshi:~$ sudo touch /etc/network/if-up.d/iptables [sudo] password for jason:jason@hoshi:~$ sudo touch /etc/network/if-up.d/iptables [sudo] password for jason: Put this in it. #!/bin/sh iptables-restore < /etc/iptables.conf#!/bin/sh iptables-restore … Read more
How to save your iptables firewall rules using the iptables-persistent package for Linux.
The iptables firewall is the built-in firewall for protecting a Linux machine from online threats. But the settings are not save upon a re-boot. This is easily alleviated by installing the iptables-persistent package for Ubuntu. Once this is installed, you will be greeted with a screen that will ask you if you wish to save … Read more
How to list all iptables rules that are set on your Linux system. This is very easy.
The iptables -L or iptables –list commands will list all of the iptables rules that are set on your Linux machine. Below is the abbreviated output of this command on my Fedora Linux system. [root@localhost homer]# iptables –list Chain INPUT (policy ACCEPT) target prot opt source destination ACCEPT all — anywhere anywhere ctstate RELATED,ESTABLISHED ACCEPT … Read more
Using iptables on a Linux system to secure your computer against Internet threats. This is important.
Securing your Linux computer with iptables is a great way to make sure that you are safer from Internet attacks. The iptables(8) system is the built in firewall for a Linux system. This makes it very easy to secure your computer. Before you change any settings, backup your iptables configuration. iptables-save > backup.confiptables-save > backup.conf … Read more