What type of route does R1 use to reach the Internet in a common configuration?

In a common configuration, routers typically use a default route to reach the Internet when specific routes to destination networks are not known. A default route serves as a catch-all route that tells the router where to send traffic destined for addresses not explicitly listed in its routing table. The default route is often represented as "0.0.0.0/0".

In this scenario, the router R1 would use a default route to reach an external network like the Internet. The provided IP address (20.20.20.1) signifies the next-hop address that R1 will forward traffic to when it doesn't have a more specific route in its routing table. This configuration is standard in many routers and is essential for allowing devices within a local network to communicate with external networks.

Using a direct connection route or routing through the LAN wouldn’t facilitate communication with the Internet as effectively, given they lack the necessary path for external addresses. Meanwhile, specifying a static route to a specific private IP (like 192.168.1.1) wouldn't be appropriate for accessing the Internet since this address commonly refers to an internal network device rather than a gateway to the Internet.