How to make rules persistent?

To make iptables rules persistent across reboots, you can follow these steps depending on your Linux distribution:

For Debian/Ubuntu:

1. Install iptables-persistent:

   sudo apt-get install iptables-persistent

2. Save Current Rules:
   During installation, you will be prompted to save your current iptables rules. If you want to save them later, you can run:

   sudo netfilter-persistent save

3. Automatically Load Rules on Boot:
   The iptables-persistent package automatically loads the saved rules on boot.

For CentOS/RHEL:

1. Install iptables-services:

   sudo yum install iptables-services

2. Save Current Rules:
   Save your current rules using:

   sudo service iptables save

3. Enable the Service:
   Ensure the iptables service is enabled to start on boot:

   sudo systemctl enable iptables

For Other Distributions:

You may need to check the specific method for your distribution, but generally, you can save the rules to a file and create a script to load them on boot.

Example Script:

You can create a script to restore rules at startup:

1. Create a script file, e.g., /etc/iptables/restore-rules.sh:

   #!/bin/bash
   iptables-restore < /path/to/your/rules.v4

2. Make it executable:

   sudo chmod +x /etc/iptables/restore-rules.sh

3. Add it to your system's startup scripts (e.g., using cron or systemd).

By following these steps, your iptables rules should persist across reboots.