Time for action – enabling IP forwarding

1. To enable IP forwarding on Linux-based operating systems, we can use any of the following methods.

   Using the sysctl command:

   sysctl -w net.ipv4.ip_forward=1

   This method doesn't need a reboot and will enable IP forwarding on the fly but will not be preserved after a reboot.

   Using the sysctl configuration file, we can add the following line in the /etc/sysctl.conf file:

   net.ipv4.ip_forward = 1

2. To enable the changes made to the /etc/sysctl.conf file, we need to run the following command:

   sysctl -p /etc/sysctl.conf

   These changes will be preserved after a reboot.

3. Enabling IP forwarding on BSD operating systems is almost similar. We can use any of the following methods:

   Using the sysctl command.

   sysctl -w net.inet.ip.forwarding=1

   This method doesn't need a reboot and will enable IP forwarding on the fly but will not be preserved after a reboot. Please note that we don't need the -w option on OpenBSD and DragonFlyBSD.

   We can add the following line in the /etc/rc.conf...