What is the primary purpose of a default route in a router's routing table?

The primary purpose of a default route in a router's routing table is to route packets that do not have a specific route. When a router receives a packet with a destination IP address that it does not have an explicit route for, it relies on the default route as a fallback. This route essentially serves as a catch-all option.

If the router cannot find the destination in its routing table, it will forward the packet to the next hop specified by the default route. This allows for more efficient routing management, as it eliminates the need to maintain detailed routes for every possible destination on the internet or in a large network. The default route is particularly useful for simplifying configurations and ensuring that all packets can be handled, even if their destinations aren't specifically defined in the routing table.