What is a Default Gateway?

A Default Gateway refers to a routing device that serves as an access point or "gateway" to other networks, notably when a device on a local network needs to communicate with devices on different networks. It acts as a node that forwards packets from the local network to destinations outside of it, typically on the broader internet.

When a device, such as a computer or printer, wants to send data outside its local network, it checks whether the destination IP address of the intended recipient is within its own subnet. If the address lies outside of the local network, the device will send its data packets to the default gateway, which then finds the most suitable route to reach the destination network. This makes the default gateway an essential component for network communication, as it enables seamless interaction between different networks.

In context, the other options refer to different roles within network infrastructure. A DNS server pertains to translating domain names into IP addresses. A backup router involved in failover provides redundancy but does not directly serve as the access point itself. An interface for connecting to local devices is related to local area network (LAN) functionality but not specifically to the routing role performed by a default gateway. Thus, the definition of a default gateway aligns perfectly with its primary function of facilitating external network