Which attribute is commonly used by Policy Based Routing to select traffic for routing, such as to a specific VRF or next hop?

Which attribute is commonly used by Policy Based Routing to select traffic for routing, such as to a specific VRF or next hop?

• A. Source IP prefix
• B. Destination IP prefix
• C. MAC address
• D. Port number

Answer: (A)

Policy Based Routing makes routing decisions by inspecting fields in the IP header and applying a policy that can override the normal destination-based route. The attribute most commonly used to steer traffic into a specific VRF or toward a chosen next hop is the source IP prefix. By matching on the origin subnet, you can consistently apply the same routing outcome to all packets from that subnet, isolating it into the desired VRF or sending it to a particular exit path, regardless of where the traffic is going. This approach is especially useful in environments with multiple customers or tenants, where each subnet should follow its own routing domain. While you could base a policy on destination IP prefixes in some cases, tying the decision to the source prefix is the standard way to implement per-subnet or per-tenant routing into a VRF or to a specific next hop. MAC addresses are layer-2 identifiers and aren’t used for IP routing decisions, and port numbers deal with application behavior rather than routing domain.

Policy Based Routing makes routing decisions by inspecting fields in the IP header and applying a policy that can override the normal destination-based route. The attribute most commonly used to steer traffic into a specific VRF or toward a chosen next hop is the source IP prefix. By matching on the origin subnet, you can consistently apply the same routing outcome to all packets from that subnet, isolating it into the desired VRF or sending it to a particular exit path, regardless of where the traffic is going. This approach is especially useful in environments with multiple customers or tenants, where each subnet should follow its own routing domain.

While you could base a policy on destination IP prefixes in some cases, tying the decision to the source prefix is the standard way to implement per-subnet or per-tenant routing into a VRF or to a specific next hop. MAC addresses are layer-2 identifiers and aren’t used for IP routing decisions, and port numbers deal with application behavior rather than routing domain.