Check Linux IP Forwarding for Access Server Routing⁠

Question: What is IP forwarding, and how do I enable it on Linux?

Answer:

IP forwarding allows a system to route traffic between networks. An example use is a system sitting between two different networks that needs to pass traffic between them.

On most Linux systems, you can turn on IP forwarding by editing the /etc/sysctl.conf file. For example, follow these steps on Ubuntu/Debian:

1. Connect to the console and get root privileges.

2. Open the sysctl.conf file in the nano text editor:

   nano /etc/sysctl.conf

3. Uncomment or add this line:

   net.ipv4.ip_forward=1

4. Press CTRL_x, Y, then ENTER to save and exit the file.

5. Run this command:

   sysctl -p

   • You've turned on IP forwarding.