Interdomain Multicasting

Example configuration

We have 2 Autonomous System in this scenarios. AS 100 and AS 200 each running OSPF as the IGP routing protocol. The requirement in this example is to configure network to forward the multicast traffic from AS 100 to AS 200. The source of multicast traffic is R3 loopback interface and the receiver is sitting at R4 in the AS 200.

In this scenario, we need to configure Interdomain MSDP. We have selected R1 and R2 as a RPs for each AS. They form the MSDP neighbor together to accomplish this. Here is the configuration.

R1
router bgp 100

 bgp log-neighbor-changes
 neighbor 192.168.1.2 remote-as 200
 !
 address-family ipv4
  redistribute ospf 1
  neighbor 192.168.1.2 activate
  no auto-summary
  no synchronization
  network 1.1.1.0 mask 255.255.255.0
 exit-address-family
 !
 address-family ipv4 multicast
  neighbor 192.168.1.2 activate
  no auto-summary
  no synchronization
 exit-address-family
!
ip forward-protocol nd

ip pim rp-address 1.1.1.1

ip msdp peer 2.2.2.2 connect-source Loopback0 remote-as 200

!

R2

router bgp 200

 bgp log-neighbor-changes

 neighbor 192.168.1.1 remote-as 100

 !

 address-family ipv4

  redistribute ospf 1

  neighbor 192.168.1.1 activate

  no auto-summary

  no synchronization

  network 2.2.2.0 mask 255.255.255.0

 exit-address-family

 !

 address-family ipv4 multicast

  neighbor 192.168.1.1 activate

  no auto-summary

  no synchronization

 exit-address-family

!

ip forward-protocol nd

!

!

no ip http server

no ip http secure-server

ip pim rp-address 2.2.2.2

ip msdp peer 1.1.1.1 connect-source Loopback0 remote-as 100

!

R3

ip pim rp-address 1.1.1.1

R4

ip pim rp-address 2.2.2.2

Verify configuration

R1#sh ip msdp summary

MSDP Peer Status Summary

Peer Address     AS    State    Uptime/  Reset SA    Peer Name

                                Downtime Count Count

2.2.2.2          200   Up       00:06:54 0     0     ?

R1#

R3#ping 239.1.1.1

Type escape sequence to abort.

Sending 1, 100-byte ICMP Echos to 239.1.1.1, timeout is 2 seconds:

Reply to request 0 from 10.1.1.2, 388 ms

R3#

R2#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

Outgoing interface flags: H - Hardware switched, A - Assert winner

 Timers: Uptime/Expires

 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.1.1.1), 01:02:18/00:03:19, RP 2.2.2.2, flags: SJC

  Incoming interface: Null, RPF nbr 0.0.0.0

  Outgoing interface list:

    FastEthernet0/1, Forward/Sparse, 01:02:18/00:03:19

(172.16.1.2, 239.1.1.1), 00:00:26/00:02:33, flags: M

  Incoming interface: FastEthernet0/0, RPF nbr 192.168.1.1

  Outgoing interface list:

    FastEthernet0/1, Forward/Sparse, 00:00:26/00:03:19

(*, 224.0.1.40), 01:08:40/00:03:21, RP 2.2.2.2, flags: SJCL

  Incoming interface: Null, RPF nbr 0.0.0.0

  Outgoing interface list:

    FastEthernet0/0, Forward/Sparse, 01:05:16/00:02:25

    FastEthernet0/1, Forward/Sparse, 01:08:40/00:03:21

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