What does policy-based routing allow a router to do?

Policy-based routing enhances a router's decision-making capabilities by allowing it to route traffic based on predefined policies rather than just traditional criteria like destination IP address. With policy-based routing, the router can evaluate various attributes of the packets, such as the source address, protocol type, and even the application type. This flexibility enables network administrators to implement specific routing behaviors based on organizational needs.

For example, traffic from a particular application may be directed through a different route than standard web traffic, regardless of their destination. This routing method is particularly valuable in scenarios where different types of traffic require distinct handling due to performance requirements, security policies, or service level agreements. By leveraging policy-based routing, organizations can optimize their network resources and improve overall traffic management.

The other options do not encompass the full functionality of policy-based routing. Routing traffic based solely on the destination is a characteristic of traditional routing methods, while filtering based on packet size and volume pertains to Quality of Service (QoS) rather than routing principles. Preventing local network traffic does not align with routing concepts as it implies a restriction rather than a method of directing traffic flow.