What is a Default Gateway?

What is a Default Gateway?

• A. The IP address of the router in the network
• B. The IP address of the DNS server
• C. The subnet mask
• D. The IP address of the firewall

Answer: (A)

A default gateway is the IP address of the router on your local network that devices send traffic to when the destination is not on the same subnet. When a device wants to reach a host outside its own local network, it first checks its subnet mask to see that the destination is not local, and then forwards the packet to this gateway. The gateway then routes the traffic toward its final destination, often out to the internet. This gateway must be reachable on the local network, typically through ARP to map the gateway's IP to its MAC address. The idea is that the router is the next hop for all non-local destinations. Why the other options aren’t correct in this context: the DNS server’s role is to translate domain names into IP addresses, not to forward traffic to other networks; the subnet mask defines the size of the local network and helps decide if a destination is local or needs to go through the gateway; the firewall’s IP address might serve as a gateway in some setups, but a default gateway is specifically the router’s IP address configured as the default route for outbound traffic.

A default gateway is the IP address of the router on your local network that devices send traffic to when the destination is not on the same subnet. When a device wants to reach a host outside its own local network, it first checks its subnet mask to see that the destination is not local, and then forwards the packet to this gateway. The gateway then routes the traffic toward its final destination, often out to the internet.

This gateway must be reachable on the local network, typically through ARP to map the gateway's IP to its MAC address. The idea is that the router is the next hop for all non-local destinations.

Why the other options aren’t correct in this context: the DNS server’s role is to translate domain names into IP addresses, not to forward traffic to other networks; the subnet mask defines the size of the local network and helps decide if a destination is local or needs to go through the gateway; the firewall’s IP address might serve as a gateway in some setups, but a default gateway is specifically the router’s IP address configured as the default route for outbound traffic.