In certain configurations, IP forwarding isn't enabled. It can be enabled by using the command: sysctl -w net.ipv4.ip_forward = 1. It is necessary because without IP forwarding packets cannot move from one subnet to another.
The command to enable IP forwarding in the Linux router's kernel is:
sysctl -w net.ipv4.ip_forward=1
This is necessary for routing packets between subnets, as IP forwarding allows the router to efficiently forward packets between different network interfaces. Without IP forwarding, inter-subnet communication would be restricted.
