What Bootstrap Router (BSR) ? How to configure Multicast PIM Bootstrap Router (BSR)?

What is Rendezvous's point?

The rendezvous point is a meeting point in the Multicast PIM sparse mode for all the multicast traffic. We have two ways to configure the Rendezvous point manually and automatically. Manual RP is for small networks and Auto RP is for large networks.

 

We have two discovery protocols for finding the Rendezvous point on the multicast network

 

1.     Auto Rendezvous point (Auto-RP)

2.     PIMv2 bootstrap router (BSR)

Multicast Bootstrap Router (BSR) 

Multicast PIM Bootstrap, also known as Protocol Independent Multicast (PIM) Bootstrap, is a protocol used in multicast routing to efficiently manage multicast traffic distribution in a network. PIM BSR router function is similar to Auto-RP but BSR is a standard-based protocol PIMv2 standard and also BSR supports IPv6 multicast. 

 

How does Multicast Bootstrap Router (BSR) work? 

 

• Candidate BSR: Bootstrap Router collects information from the available Rendezvous points in the multicast network and advertises it on PIM-enabled interfaces throughout the multicast network. 
• Candidate Rendezvous Point: Uses unicast PIM to advertise itself to BSR. 
• BSR messages are sent hop-by-hop using multicast address 224.0.0.13 with a TTL of 1. These messages are routed only within the local segment.
• When a multicast router receives a BSR message, it re-sends it to all other PIM-enabled interfaces.
• BSR messages contain information about the BSR itself and RP-to-group mappings.

BSR vs. Auto-RP:

• BSR is a standard protocol included in PIMv2, whereas Auto-RP is a Cisco proprietary protocol.
• BSR uses unicast packets for RP announcements, while Auto-RP uses multicast.
• BSR does not select the RP; it advertises all RPs with their associated multicast groups, allowing multicast routers to choose the RP they prefer.

 

 

Let's see the topology as per the diagram?

 

 

Topology:-https://youtu.be/vWHXTLczQUs?si=bduAb8ruzpumR8O1

 

 

Goal:

 

1.     configure the topology as per the diagram 

2.     configure IP addresses as per the topology

3.     configure IGP OSPF and advertise directly connected interfaces

4.     enable Multicasting on all the router

5.     configure PIM-SM on all interfaces 

6.     configure IGMP-group  224.50.50.50 on router 5 fa0/0

7.     configure Router 5 to advertise themselves as Rendezvous Point for all the groups

 

 

 

R1(config)#interface serial 4/0
R1(config-if)#ip address 1.1.1.1 255.0.0.0
R1(config-if)#no shutdown
R1(config-if)#exit

R1(config)#interface fastethernet 0/0
R1(config-if)#ip address 10.1.1.1 255.0.0.0
R1(config-if)#no shutdown
R1(config-if)#no keepalive
R1(config-if)#exit
 
R2(config)#interface serial 4/0
R2(config-if)#ip address 1.1.1.2 255.0.0.0
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface serial 4/1
R2(config-if)#ip address 2.2.2.1 255.0.0.0
R2(config-if)#no shutdown
R2(config-if)#exit

R2(config)#interface fastEthernet 0/0
R2(config-if)#ip address 20.1.1.1 255.0.0.0
R2(config-if)#no shutdown
R2(config-if)#no keepalive
R2(config-if)#exit
 
R3(config)#interface serial 4/1
R3(config-if)#ip address 2.2.2.2 255.0.0.0
R3(config-if)#no shutdown
R3(config-if)#exit

R3(config)#interface serial 4/2
R3(config-if)#ip address 3.3.3.1 255.0.0.0
R3(config-if)#no shutdown
R3(config-if)#exit

R3(config)#interface fastethernet 0/0
R3(config-if)#ip address 30.1.1.1 255.0.0.0
R3(config-if)#no keepalive
R3(config-if)#no shutdown
R3(config-if)#exit
 
R4(config)#interface serial 4/2
R4(config-if)#ip address 3.3.3.2 255.0.0.0
R4(config-if)#no shutdown
R4(config-if)#exit

R4(config)#interface serial 4/4
R4(config-if)#ip address 5.5.5.2 255.0.0.0
R4(config-if)#no shutdown
R4(config-if)#exit

R4(config)#interface fastethernet 0/0
R4(config-if)#ip address 40.1.1.1 255.0.0.0
R4(config-if)#no shutdown
R4(config-if)#no keepalive
R4(config-if)#exit
 
R5(config)#interface serial 4/4
R5(config-if)#ip address 5.5.5.1 255.0.0.0
R5(config-if)#no shutdown
R5(config-if)#exit

R1(config)#router ospf 100
R1(config-router)#network 1.0.0.0 0.255.255.255 area 0
R1(config-router)#network 10.0.0.0 0.255.255.255 area 0
R1(config-router)#exit
 
*Mar 16 12:21:51.463: %OSPF-5-ADJCHG: Process 100, Nbr 20.1.1.1 on Serial4/0 from LOADING to FULL, Loading Done
 
R2(config)#router ospf 100
R2(config-router)#network 20.0.0.0 0.255.255.255 area 0
R2(config-router)#network 1.0.0.0 0.255.255.255 area 0
R2(config-router)#network 2.0.0.0 0.255.255.255 area 0
R2(config-router)#exit
 
*Mar 16 12:22:02.455: %OSPF-4-DUP_RTRID_NBR: OSPF detected duplicate router-id 20.1.1.1 from 2.2.2.2 on interface Serial4/1
*Mar 16 12:21:51.299: %OSPF-5-ADJCHG: Process 100, Nbr 10.1.1.1 on Serial4/0 from LOADING to FULL, Loading Done
 
R3(config)#router ospf 100
R3(config-router)#network 30.0.0.0 0.255.255.255 area 0
R3(config-router)#network 2.0.0.0 0.255.255.255 area 0
R3(config-router)#network 3.0.0.0 0.255.255.255 area 0
R3(config-router)#exit
 
R4(config)#router ospf 100
R4(config-router)#network 40.0.0.0 0.255.255.255 area 0
R4(config-router)#network 3.0.0.0 0.255.255.255 area 0
R4(config-router)#network 5.0.0.0 0.255.255.255 area 0
R4(config-router)#exit
*Mar 16 12:34:31.987: %OSPF-5-ADJCHG: Process 100, Nbr 50.1.1.1 on Serial4/4 from LOADING to FULL, Loading Done
*Mar 16 12:32:10.451: %OSPF-5-ADJCHG: Process 100, Nbr 30.1.1.1 on Serial4/2 from LOADING to FULL, Loading Done
 
R5(config)# router ospf 100
R5(config-router)#network 50.0.0.0 0.255.255.255 area 0
R5(config-router)#network 5.0.0.0 0.255.255.255 area 0
R5(config-router)#exit
*Mar 16 12:34:31.687: %OSPF-5-ADJCHG: Process 100, Nbr 40.1.1.1 on Serial4/4 from LOADING to FULL, Loading Done
 
 
R1(config)#ip multicast-routing
R1(config)#interface serial 4/0
R1(config-if)#ip pim sparse-mode
R1(config-if)#exit
 
R1(config)#interface fastethernet 0/0
R1(config-if)#ip pim sparse-mode
R1(config-if)#exit
 
R2(config)#ip multicast-routing
R2(config)#interface serial 4/0
R2(config-if)#ip pim sparse-mode
R2(config-if)#exit
 
R2(config)#interface serial 4/1
R2(config-if)#ip pim sparse-mode
R2(config-if)#exit
R2(config)#exit
 
*Mar 16 12:46:14.519: %PIM-5-NBRCHG: neighbor 1.1.1.1 UP on interface Serial4/0
*Mar 16 12:46:58.943: %PIM-5-NBRCHG: neighbor 2.2.2.2 UP on interface Serial4/1
R3(config)#ip multicast-routing
R3(config)#interface serial 4/1
R3(config-if)#ip pim sparse-mode
R3(config-if)#exit
 
R3(config)#interface serial 4/2
R3(config-if)#ip pim sparse-mode
R3(config-if)#exit
 
R3(config)#interface fastethernet 0/0
R3(config-if)#ip pim sparse-mode
R3(config-if)#exit
*Mar 16 12:46:58.947: %PIM-5-NBRCHG: neighbor 2.2.2.1 UP on interface Serial4/1
*Mar 16 12:47:59.979: %PIM-5-NBRCHG: neighbor 3.3.3.2 UP on interface Serial4/2
 
 
R4(config)#ip multicast-routing
R4(config)#interface serial 4/2
R4(config-if)#ip pim sparse-mode
R4(config-if)#exit
R4(config)#interface serial 4/3
R4(config-if)#ip pim sparse-mode
R4(config-if)#exit
 
*Mar 16 12:47:59.783: %PIM-5-NBRCHG: neighbor 3.3.3.1 UP on interface Serial4/2
*Mar 16 13:09:18.855: %PIM-5-NBRCHG: neighbor 5.5.5.1 UP on interface Serial4/4
 
R5(config)#interface loopback 0
R5(config-if)#ip address 15.1.1.1 255.255.255.0
R5(config-if)#no shutdown
R5(config-if)#exit
R5(config)#router ospf 100
R5(config-router)#network 15.1.1.0 255.0.0.0 area 0
R5(config-router)#exit
 
R5(config)#ip multicast-routing
R5(config)#interface serial 4/4
R5(config-if)#ip pim sparse-mode
R5(config-if)#exit
 
R5(config)#interface loopback 0
R5(config-if)#ip pim sparse-mode
R5(config-if)#exit
 
R5(config)#interface fastEthernet 0/0
R5(config-if)#ip igmp join-group 224.50.50.50
R5(config-if)#exit
 
R5(config)#interface f0/0
R5(config-if)#ip pim sparse-mode
R5(config-if)#exit
 
*Mar 16 13:42:16.819: %PIM-5-DRCHG: DR change from neighbor 0.0.0.0 to 50.1.1.1 on interface FastEthernet0/0
 
R5(config)#ip pim rp-candidate loopback 0
R5(config)#ip pim bsr-candidate loopback 0
 
R5(config)#do show ip pim rp mapping
PIM Group-to-RP Mappings
This system is a candidate RP (v2)
This system is the Bootstrap Router (v2)
 
Group(s) 224.0.0.0/4
  RP 15.1.1.1 (?), v2
    Info source: 15.1.1.1 (?), via bootstrap, priority 0, holdtime 150
         Uptime: 00:00:58, expires: 00:01:29
 
R1#show ip pim rp mapping
PIM Group-to-RP Mappings
 
Group(s) 224.0.0.0/4
  RP 15.1.1.1 (?), v2
    Info source: 15.1.1.1 (?), via bootstrap, priority 0, holdtime 150
         Uptime: 00:07:26, expires: 00:02:01
 
 
R1#ping 224.50.50.50
 
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 224.50.50.50, timeout is 2 seconds:
 
Reply to request 0 from 5.5.5.1, 116 ms
Reply to request 0 from 5.5.5.1, 144 ms
 
 
R2#show ip pim rp mapping
PIM Group-to-RP Mappings
 
Group(s) 224.0.0.0/4
  RP 15.1.1.1 (?), v2
    Info source: 15.1.1.1 (?), via bootstrap, priority 0, holdtime 150
         Uptime: 00:41:52, expires: 00:01:47
R2#ping 224.50.50.50
 
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 224.50.50.50, timeout is 2 seconds:
 
Reply to request 0 from 5.5.5.1, 108 ms
Reply to request 0 from 5.5.5.1, 128 ms
 
R3#show ip pim neighbor
PIM Neighbor Table
Mode: B - Bidir Capable, DR - Designated Router, N - Default DR Priority,
      S - State Refresh Capable
Neighbor          Interface                Uptime/Expires    Ver   DR
Address                                                            Prio/Mode
2.2.2.1           Serial4/1                01:06:01/00:01:35 v2    1 / S P
3.3.3.2           Serial4/2                01:05:00/00:01:24 v2    1 / S P
R3#
R3#show ip pim rp mapping
PIM Group-to-RP Mappings
 
Group(s) 224.0.0.0/4
  RP 15.1.1.1 (?), v2
    Info source: 15.1.1.1 (?), via bootstrap, priority 0, holdtime 150
         Uptime: 00:42:53, expires: 00:01:44
 
R4#show ip pim interface
 
Address          Interface                Ver/   Nbr    Query  DR     DR
                                          Mode   Count  Intvl  Prior
3.3.3.2          Serial4/2                v2/S   1      30     1      0.0.0.0
4.4.4.1          Serial4/3                v2/S   0      30     1      0.0.0.0
5.5.5.2          Serial4/4                v2/S   1      30     1      0.0.0.0
R4#show ip pim rp mapping
PIM Group-to-RP Mappings
 
Group(s) 224.0.0.0/4
  RP 15.1.1.1 (?), v2
    Info source: 15.1.1.1 (?), via bootstrap, priority 0, holdtime 150
         Uptime: 00:43:22, expires: 00:02:18

R4#ping 224.50.50.50
 
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 224.50.50.50, timeout is 2 seconds:
 
Reply to request 0 from 5.5.5.1, 24 ms
Reply to request 0 from 5.5.5.1, 64 ms
 

 
R2#show ip pim bsr-router
PIMv2 Bootstrap information
  BSR address: 15.1.1.1 (?)
  Uptime:      00:44:28, BSR Priority: 0, Hash mask length: 0
  Expires:     00:01:54
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