What is the role of a default gateway for hosts in a subnet?

• A. It provides a path to reach destinations outside the local subnet.
• B. It assigns IP addresses to hosts.
• C. It filters traffic entering the subnet.
• D. It determines the subnet mask.

Answer: (A)

A default gateway serves as the exit point for traffic destined outside the local subnet. When a host wants to reach a device on another network, it first checks whether the destination is in its own subnet. If it isn’t, the host sends the packet to the gateway’s IP address. The gateway then uses its routing table to forward the packet toward the next hop toward the destination, and this process continues through the network until the destination is reached. If the destination is inside the local subnet, the host communicates directly with it on the local link.

The gateway isn’t responsible for assigning IP addresses, filtering traffic, or determining the subnet mask. IP addresses are typically assigned by DHCP, filtering is done by firewalls or ACLs, and the subnet mask is part of the host’s or network’s addressing configuration.