CentOS / Red Hat Linux IP Forwarding How To

How do I enable IP forwarding under RHEL / Red Hat / Fedora / CentOS Linux operating systems?

You can easily turn on IP forwarding under Linux operating system by modifying Linux kernel variables (MIB).

Linux Enable IP Forwarding

Open /etc/sysctl.conf file using a text editor, enter:
# vi /etc/sysctl.conf
Set net.ipv4.ip_forward to 1, enter:

 
net.ipv4.ip_forward = 1

Save and close the file. Reload the changes by typing the following command:
# sysctl -p