This Lab deals with MSDP, Multicast Source Discovery Protocol, which allows RPs in different domains to exchange information about Multicast Sources. This is used in PIM Sparse mode. Since RPs know about the receivers in its own domains but couldn't know about sources in other domains, MSDP is used to exchange the information about sources so that multicast traffic can flow between domains. Below is a good description on MSDP.
Config:
R2 and R4 are RPs for their respective PIM Sparse multicast domains, they are also edge routers in their own domains and peer via eBGP.
hostname R2
!
no ip domain lookup
ip multicast-routing
!
interface Loopback0
ip address 150.1.2.2 255.255.255.255
!
interface Serial1/0
no ip address
encapsulation frame-relay
serial restart-delay 0
no frame-relay inverse-arp
!
interface Serial1/0.21 point-to-point
ip address 150.1.12.2 255.255.255.0
ip pim sparse-mode
snmp trap link-status
frame-relay interface-dlci 201
!
interface FastEthernet2/0
ip address 150.1.24.2 255.255.255.0
duplex auto
speed auto
!
router ospf 1
log-adjacency-changes
network 150.1.2.2 0.0.0.0 area 0
network 150.1.12.2 0.0.0.0 area 0
default-information originate always
!
router bgp 1
no synchronization
bgp log-neighbor-changes
redistribute ospf 1
neighbor 150.1.24.4 remote-as 2
no auto-summary
!
ip pim rp-address 150.1.24.2
ip msdp peer 150.1.24.4 remote-as 2
R4
hostname R4
!
no ip domain lookup
ip multicast-routing
!
interface Loopback0
ip address 150.1.4.4 255.255.255.255
!
interface Serial1/0
no ip address
encapsulation frame-relay
serial restart-delay 0
no frame-relay inverse-arp
!
interface Serial1/0.45 point-to-point
ip address 150.1.45.4 255.255.255.0
ip pim sparse-mode
snmp trap link-status
frame-relay interface-dlci 405
!
interface FastEthernet2/0
ip address 150.1.24.4 255.255.255.0
duplex auto
speed auto
!
router ospf 1
log-adjacency-changes
network 150.1.4.4 0.0.0.0 area 0
network 150.1.45.4 0.0.0.0 area 0
default-information originate always
!
router bgp 2
no synchronization
bgp log-neighbor-changes
redistribute ospf 1
neighbor 150.1.24.2 remote-as 1
no auto-summary
!
ip pim rp-address 150.1.24.4
ip msdp peer 150.1.24.2
Verification:
R6 - router closest to the receiver
R6#sh ip mroute
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group,
V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 224.1.1.1), 00:00:20/stopped, RP 150.1.24.4, flags: SJC
Incoming interface: FastEthernet1/0, RPF nbr 150.1.56.5
Outgoing interface list:
FastEthernet1/1, Forward/Sparse, 00:00:20/00:02:39
(10.1.37.7, 224.1.1.1), 00:00:19/00:02:41, flags: JT
Incoming interface: FastEthernet1/0, RPF nbr 150.1.56.5
Outgoing interface list:
FastEthernet1/1, Forward/Sparse, 00:00:19/00:02:40
(*, 224.0.1.40), 00:00:20/00:02:39, RP 150.1.24.4, flags: SJPCL
Incoming interface: FastEthernet1/0, RPF nbr 150.1.56.5
Outgoing interface list: Null
R6#
