What is the purpose of a default gateway address on a host?

• A. It is the next-hop router used to reach destinations outside the local subnet.
• B. It is the DNS server used for domain name resolution.
• C. It is the broadcast address of the local network.
• D. It is the IP address of the DHCP server.

Answer: (A)

The default gateway is the next-hop router the host uses to reach destinations outside its own local subnet. When a host needs to send a packet to an IP address that isn’t on the same network, it forwards the packet to the gateway’s IP on the local network. The gateway then takes responsibility for routing that packet toward the destination, whether that means sending it to another network, to a different router, or to the internet. If the destination is within the same subnet, the host can reach it directly without using the gateway, by ARP’ing for the destination’s MAC address.

This isn’t the DNS server, which handles translating domain names to IP addresses, nor the broadcast address, which is used to send a message to all devices on the local network, nor the DHCP server’s IP, which is about assigning network configuration. The gateway’s role is specifically to provide a path to networks beyond the local subnet.