https://github.com/mfinelli/firewall

Set of bash scripts to generate a firewall in Linux using iptables. Based on: https://wiki.archlinux.org/index.php/Simple_stateful_firewall
https://github.com/mfinelli/firewall

bash firewall iptables linux shell

Last synced: about 1 month ago
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Set of bash scripts to generate a firewall in Linux using iptables. Based on: https://wiki.archlinux.org/index.php/Simple_stateful_firewall

• Host: GitHub
• URL: https://github.com/mfinelli/firewall
• Owner: mfinelli
• License: mit
• Created: 2015-03-30T18:53:58.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2015-05-03T01:52:17.000Z (over 9 years ago)
• Last Synced: 2024-05-08T22:12:25.970Z (8 months ago)
• Topics: bash, firewall, iptables, linux, shell
• Language: Shell
• Homepage:
• Size: 184 KB
• Stars: 2
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md
  • Changelog: changelog.md
  • License: LICENSE

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README

        
# firewall

A script to manage the firewall on Linux using iptables.

## Standard Usage

There is only one script that you need to run to manage the firewall but to which you can pass various commands. They should generally be run in the order presented. Note that all commands need to be executed with root privileges (e.g., by using sudo).

### Reset rules

This command resets the iptables to an empty state, allowing all traffic.

    # ./firewall reset

### Stateful firewall

This sets the firewall to be like the Arch Linux guide. No ports are left open so you shouldn't run this from an SSH session.

    # ./firewall stateful

### Port scanner

Attempt to mitigate port scanner attacks.

    # ./firewall portscanner

### Sshguard

Once you've installed sshguard you can add rules to your iptables. This will also automatically setup sshguard to work on port 22. You will still need to open port 22 in order to connect via ssh. (See below)

    # ./firewall sshguard

### Open

You can open individual ports in the firewall with this script. There are two ways to call this script. You can pass one of the predefined rules or an individual port number along with the protocol. To open with a predefined rule (e.g., SSH through port 22):

    # ./firewall open ssh

The complete list of supported rules is:

* SSH: port 22

* Web: ports 80 and 443

* HTTP: port 80

* HTTPS: port 443

* DNS: port 53

To open an arbitrary port:

    # ./firewall open 22 tcp

Or:

    # ./firewall open 53 udp

## What next?

After running the scripts and opening your desired ports you should save the rules and make sure the iptables service is enabled with e.g., systemd:

    # iptables-save > /etc/iptables/iptables.rules

    # systemctl [start|enable] iptables

    # systemctl [start|enable] sshguard

Obviously, setting up your firewall is only a start. You should take every effort to lock your machine down by disabling root login through SSH, for example.

## Disclaimer

I don't claim to know anything about security. These scripts were created by basically following the guide at the Arch Linux wiki for my own personal use. It's great if you want to use them as well, but I am not liable if your machine gets owned. For more information see the license.