Multicast - Bootstrap Router

Overview

Bootstrap router or BSR is a standards based method to elect and exchange PIM messages similar to Cisco's AutoRP feature. BSR does not use PIM dense mode unlike AutoRP and instead uses PIM messages on a hop by hop basis. Each router performs an RPF check against the PIM messages and if they pass the rpf check then the messages are flooded out all PIM enabled interfaces.

Concepts tested

• Configuring PIM sparse mode
• Configuring basic BSR with a single BSR RP
• Verify configuration

Topology

Lab Tasks

• Configure PIM sparse mode on all interfaces along the path between the receiver and source hosts
• Configure R4 as both the RP candidate and BSR router for the group 232.0.0.0 /5
•  Verify your configuration

GNS3 configuration file, requires IOS v15 for the 7200 router: Link


Solution

R1(config)#ip multicast-routing
R1(config)#int g0/0
R1(config-if)#ip pim sparse-mode
R1(config-if)#exit

R2(config)#ip multicast-routing

R2(config)#int g0/0

R2(config-if)#ip pim sparse-mode

R2(config-if)#exit

R2(config)#int g1/0

R2(config-if)#ip pim sparse-mode

R2(config-if)#exit

R3(config)#ip multicast-routing
R3(config)#int g0/0
R3(config-if)#ip pim sparse-mode
R3(config-if)#exit

R3(config)#int g1/0

R3(config-if)#ip pim sparse-mode

R3(config-if)#exit

R4(config)#ip multicast-routing

R4(config)#int g0/0

R4(config-if)#ip pim sparse-mode

R4(config-if)#exit

R4(config)#int g1/0

R4(config-if)#ip pim sparse-mode

R4(config-if)#exit

R4(config)#int g2/0

R4(config-if)#ip pim sparse-mode

R4(config-if)#exit

R4(config)#ip access-list standard BSR_GROUPS

R4(config-std-nacl)#permit 232.0.10.0 0.0.7.255

R4(config-std-nacl)#exit

R4(config)#int loopback 0

R4(config-if)#ip add 4.4.4.4 255.255.255.0

R4(config-if)#ip pim sparse-mode

R4(config-if)#exit

R4(config)#ip pim bsr-candidate loopback 0

R4(config)#ip pim rp-candidate loopback 0 group-list BSR_GROUPS priority 0

R5(config)#ip multicast-routing
R5(config)#int g0/0
R5(config-if)#ip pim sparse-mode
R5(config-if)#exit

Verification

R4#debug ip pim bsr

*Dec  2 06:10:53.647: PIM-BSR(0): RP-set for 232.0.0.0/5
*Dec  2 06:10:53.647: PIM-BSR(0):   RP(1) 4.4.4.4, holdtime 150 sec priority 0
*Dec  2 06:10:53.655: PIM-BSR(0): Bootstrap message for 4.4.4.4 originated
*Dec  2 06:11:45.787: PIM-BSR(0): Build v2 Candidate-RP advertisement for 4.4.4.4 priority 0, holdtime 150
*Dec  2 06:11:45.791: PIM-BSR(0):  Candidate RP's group prefix 232.0.0.0/5
*Dec  2 06:11:45.795: PIM-BSR(0): Send Candidate RP Advertisement to 4.4.4.4
*Dec  2 06:11:45.807: PIM-BSR(0):  RP 4.4.4.4, 1 Group Prefixes, Priority 0, Holdtime 150

R3#sh ip pim bsr-router
PIMv2 Bootstrap information
  BSR address: 4.4.4.4 (?)
  Uptime:      00:19:15, BSR Priority: 0, Hash mask length: 0
  Expires:     00:02:03
R3#sh ip pim rp map
PIM Group-to-RP Mappings

Group(s) 232.0.0.0/5
  RP 4.4.4.4 (?), v2
    Info source: 4.4.4.4 (?), via bootstrap, priority 0, holdtime 150
         Uptime: 00:07:17, expires: 00:02:18