The Default Gateway's Job

A device can talk directly to others on its own subnet, but how does it reach a server on the other side of the world? The answer is the default gateway, the router that connects your local network to everything beyond it. This lesson explains the gateway role and how a device decides when to use it. It is foundational to all routing.

Before sending a packet, a device asks a key question: is the destination on my local subnet or not? It uses its IP address and subnet mask to figure this out. If the destination falls within the local subnet, the device delivers the frame directly. If not, the destination is remote, and the device must hand the packet to its default gateway.