PBR Support for Multiple Tracking Options

Object tracking is an independent process that monitors objects such as the following:

• State of the line protocol of an interface
• Existence of an entry in the routing table
• Results of a Service Assurance Agent (SAA) operation, such as a ping

Clients such as Hot Standby Router Protocol (HSRP), Virtual Router Redundancy Protocol (VRRP), Gateway Load Balancing Protocol (GLBP), and (with this feature) PBR can register their interest in specific, tracked objects and then take action when the state of the objects changes.

The PBR Support for Multiple Tracking Options feature gives PBR access to all the objects that are available through the tracking process. The tracking process provides the ability to track individual objects--such as ICMP ping reachability, routing adjacency, an application running on a remote device, a route in the Routing Information Base (RIB)--or to track the state of an interface line protocol.

Object tracking functions in the following manner. PBR will inform the tracking process that a certain object should be tracked. The tracking process will in turn notify PBR when the state of that object changes.

1.    enable

2.    configure terminal

3.    ip sla monitor operation-number

4.    type echo protocol ipIcmpEcho {destination-ip-address| destination-hostname}[source-ipaddr {ip-address| hostname} | source-interface interface-name]

5.    exit

6.    ip sla monitor schedule operation-number [life {forever | seconds}] [start-time {hh : mm[: ss] [month day | day month] | pending | now | after hh : mm : ss}] [ageout seconds] [recurring]

7.    track object-number rtr entry-number [reachability| state]

8.    delay {up seconds [down seconds] | [up seconds] down seconds}

9.    exit

10.    interface type number

11.    ip address ip-address mask [secondary]

12.    ip policy route-map map-tag

13.    exit

14.    route-map map-tag [permit | deny] [sequence-number]

15.    set ip next-hop verify-availability [next-hop-address sequence track object]

16.    end

17.    show track object-number

18.    show route-map [map-name| all| dynamic]

Router# show track 123
Track 123
  Response Time Reporter 1 reachability
  Reachability is Up
    2 changes, last change 00:00:33
  Delay up 60 secs, down 30 secs
  Latest operation return code: OK
  Latest RTT (millisecs) 20
  Tracked by:
    ROUTE-MAP 0

Router# show route-map alpha
route-map alpha, permit, sequence 10
  Match clauses:
  Set clauses:
    ip next-hop verify-availability 10.1.1.1 10 track 123  [up]
  Policy routing matches: 0 packets, 0 bytes