PBR:

• Policy-Based Routing (PBR) is a method used in Cisco IOS for customizing the routing of packets.
• PBR involves using a route map to determine how packets are routed instead of following the default shortest path.
• PBR is essentially Route Maps
• It is useful for various purposes like ensuring equal access, protocol-sensitive routing, source-sensitive routing, or routing based on traffic type.
• PBR offers more flexibility than traditional destination-based routing.
• To enable PBR, you must create a route map specifying match criteria and actions for matched packets.
• Apply PBR to an interface using the ip policy route-map map-tag command in interface configuration mode.
• PBR disables fast switching for packets arriving on the specified interface.
• Define route maps with route-map map-tag [permit | deny] [sequence-number] in global configuration mode.
• Under the route map configuration, use the set ip next-hop command to specify the next hop for policy-based routing.
• You can define packet matching criteria using match length, match ip address, or a combination of both in route map configuration.
• No match clause in the route map matches all packets.
• To view the cache entries in the policy route cache, use the show ip cache policy command.