BSR :
1 BSR Candidate Selected First, Using Hop By Hop Flooding/224.0.0.13, Low Priority wins in case multiple BSR,if no priority set than default
Highest IP address wins.
2 Candidate RP unicast message to elected BSR
3 BSR Messages containing RP-Set flooded Hop-by-Hope.
BSR/(Mapping Agent in AutoRP) needs to be selected first, BSR are
advertised on Hop-by-Hop basis as PIM v2/BootStrap Message.
Following Message
shows that R6/10.1.156.6 sending this message with BSR : 10.1.156.6.
Router R6 is configured with : ip pim bsr-candidate f0/1 0
10 & PIM v2 is enables along the path. Wire shark Capture for
STEP 1 : BSR Candidate Selection
STEP 2 : Candidate-RP unicast to BSR Router with RP address
Info. In this case RP is 7.7.7.7.
R7(config)#ip pim rp-candidate lo7 pri 3
STEP 3 : BSR Router Messages contains RP-Set Flooded
Hop-by-Hope. You can see the RP Count is 1.
AUTO RP :
Candidate RP( in our case 1.1.1.1) announce multicast to the 224.0.1.39 address .
following is configured on Router R1 : Candidate RP actually Route this traffic
. multicast traffic destined to the
group 224.0.1.39 is being actually routed throughout the multicast domain in
order to reach the Auto-RP MA. Default TTL is 16 in ourcase we have defined the
TTL 5.
ip pim
send-rp-announce Loopback1 scope 5 ( Where 5 is the TTL Value you can see in
the Packet)
Mapping Agent in Our Case Router R7 send RP Discovery packet/Group
to RP Mapping to the Multicast Group 224.0.1.40. if multiple RP Candidate than
MA will choose highest IP address as RP.
Following is configured on the Router R7.
ip pim
send-rp-discovery Loopback7 scope 6. Ip pim auto rp listener command will be
needed to listern for the 224.0.1.40 message.
