Overview
Policy-based routing (PBR) uses user-defined policies to route packets. A policy can specify the next hop for packets that match specific criteria such as ACLs.
A device forwards received packets using the following process:
The device uses PBR to forward matching packets.
If the packets do not match the PBR policy or the PBR-based forwarding fails, the device uses the routing table, excluding the default route, to forward the packets.
If the routing table-based forwarding fails, the device uses the default next hop or default output interface defined in PBR to forward packets.
If the default next hop or default output interface-based forwarding fails, the device uses the default route to forward packets.
PBR includes local PBR and interface PBR.
Local PBR guides the forwarding of locally generated packets, such as the ICMP packets generated by using the ping command.
Interface PBR guides the forwarding of packets received on an interface only.