What is the role of the default gateway in a DHCP configuration?

The default gateway in a DHCP configuration is crucial for routing traffic that is destined for networks outside the local subnet. When a device is assigned an IP address via DHCP, it also receives the default gateway address, which typically points to the router on the same local network. This router is responsible for forwarding packets from the local network to external networks, allowing devices to communicate beyond their immediate area. Without a correctly configured default gateway, devices may only communicate with others on the same subnet and would be unable to access the internet or reach other networks.

The other choices highlight different functionalities that are not directly related to the role of the default gateway. For example, alternate DNS servers would be specified to help resolve domain names to IP addresses, but they do not affect traffic routing. Similarly, a backup DHCP server is intended to ensure availability of IP address allocation but does not play a part in directing network traffic. Subnet exclusions are used to specify which IP addresses within a subnet should not be assigned by the DHCP server, but they do not involve routing functions. Thus, the primary role of the default gateway is indeed to route traffic out of the local network.