Policy Based Routing is the process of using a route map to specify an attribute other that the destination ip address like with the traditional routing protocol, then based on these attributes, you define which path that will be used to route a packet.
PBR can select policies based on the following conditions:
- IP address of the source or the destination.
- The port of the source or the destination.
- Network Protocols
- The size of data packets
With Cisco Secure Firewall new release, PBR can provide intelligent routing with Path Monitoring achieving application aware routing based on dynamics metrics.
Typically, in PBR, traffic is forwarded through egress interfaces based on the priority value (interface cost) configured on them. From management center version 7.2, PBR uses IP-based path monitoring to collect the performance metrics (RTT, jitter, packet-lost, and MOS) of the egress interfaces. PBR uses the metrics to determine the best path (egress interface) for forwarding the traffic. Path monitoring periodically notifies PBR about the monitored interface whose metric got changed. PBR retrieves the latest metric values for the monitored interfaces from the path monitoring database and updates the data path.
