vi /etc/sysctl.conf net.ipv4.ip_forward=1

vi /etc/sysctl.conf net.ipv4.ip_forward=1

View Answer

Answer: /proc is the virtual filesystem, containing the information about the running kernel.

To change the parameter of running kernel you should modify on /proc. From Next reboot the system, kernel will take the value from /etc/sysctl.conf.