Although not directly related to the route command, if you need to turn on IP forwarding on a host, one of the ways is to echo a “1” into the /proc/sys/net/ipv4/ip_forward file. This effectively turns on the forwarding of traffic between the different interfaces on the machine. For example:
echo 1 > /proc/sys/net/ipv4/ip_forward
This section assumes that you know how to use DHCP and that you understand that IPs are leased from the DHCP server by the client for a specified period of time, timing out and expiring unless renewed by the client utilities mentioned later in this section.