Which instance type is used when configuring filter-based forwarding?

Filter-based forwarding (FBF) is a method used in networking to route packets based on specific fields in the packet header, rather than the routing table. In this context, the forwarding instance type that is utilized for filter-based forwarding is indeed the forwarding instance.

When configuring filter-based forwarding, it's important to understand that it allows for the differentiation of forwarding behavior based on certain criteria. This is particularly useful in scenarios where different types of traffic are handled differently without needing to create separate routing tables for each instance. The forwarding instance serves as a logical construct that allows the router to apply specific policies and actions to incoming packets.

The other options, while related to various networking configurations, do not specifically pertain to the FBF configuration:

• The "vrf" option refers to Virtual Routing and Forwarding, which is used to create multiple virtual routers within a single physical router but does not directly define FBF.

• The "virtual-router" may imply a conceptual virtual router implementation but lacks the specificity of a direct implementation for FBF.

• The "fbf" option itself would suggest an abbreviation but is not a valid instance type used in filter-based forwarding configurations in routing.

Thus, the forwarding instance type is the correct choice for implementing filter-based forwarding,