Linux Kernel Settings
IP forwarding
For a Linux host to operate as an IP Router, IP forwarding must be enabled.
View IP Forwarding state
# sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 0
Turn on IP Forwarding
# sysctl -w net.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
Turn on IP forwarding permanently / on system boot
# nano /etc/sysctl.conf
net.ipv4.ip_forward = 1