Which command is utilized to advertise a default route into OSPF?

The command used to advertise a default route into OSPF is “default-information originate.” This command is essential because it allows a router to inject a default route (typically 0.0.0.0/0) into the OSPF routing domain. When you use this command, OSPF will advertise the default route to its neighboring routers, enabling them to know how to reach destinations that are not explicitly listed in their OSPF routing tables.

The “always” keyword in the command allows the router to send out the default route even if it does not have a default route in its own routing table. This is especially useful in environments where you want all routers to have a uniform understanding of the way to reach all unknown addresses, typically directed towards a gateway or internet access point.

The other options do not correctly serve the purpose of advertising a default route in OSPF. For instance, terms such as "router ospf default," "advertise default route," and "network default route" do not correspond to valid commands in OSPF configuration. Understanding the functionality and proper syntax of OSPF commands is crucial for efficient routing and network management.