Here is a very new lab to GNS3-Labs which we havent had before. We have plenty of OSPF, RIP and all the other common routing protocols and what not. Pierky has created this very cool lab featuring Multicast, PIM Sparse-mode, Anycast RP, MSDP. Hope you enjoy!

A source (Sender) needs to send a multicast ping to some receivers (R0, R1 and R2) on multicast group 239.1.2.3.

SW1 and SW2 have equal-cost paths trought C1 and C2; all links are L3, ip pim sparse-mode and EIGRP are running.

C1 and C2 are RPs (on Anycast IP 192.168.1.254) and MSDP peers:

hostname C1 ! interface Loopback0 ip address 192.168.1.254 255.255.255.255 ! interface Loopback1 ip address 192.168.1.1 255.255.255.255 ! ip msdp peer 192.168.1.2 connect-source Loopback1 ip msdp originator-id Loopback1

hostname C2 ! interface Loopback0 ip address 192.168.1.254 255.255.255.255 ! interface Loopback1 ip address 192.168.1.2 255.255.255.255 ! ip msdp peer 192.168.1.1 connect-source Loopback1 ip msdp originator-id Loopback1

Before starting to ping the multicast group from Sender, I suggest you to ping R0, R1 and R2, to wake up connections.

Let R0 and R1 join the 239.1.2.3 group on fa0/0, leaving R2 out:

conf t
int fa0/0
ip igmp join-group 239.1.2.3

At this point, SW1 and C2 know they have some receivers for the group:

SW1#show 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

(*, 239.1.2.3), 00:00:21/00:02:57, RP 192.168.1.254, flags: SJC
Incoming interface: FastEthernet0/4, RPF nbr 192.168.0.3
Outgoing interface list:
FastEthernet0/2, Forward/Sparse, 00:00:11/00:02:48
FastEthernet0/1, Forward/Sparse, 00:00:21/00:02:57

C2#show ip mroute
IP Multicast Routing Table
[cut]

(*, 239.1.2.3), 00:00:28/00:03:01, RP 192.168.1.254, flags: S
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
FastEthernet0/1, Forward/Sparse, 00:00:28/00:03:01

On Sender, start pinging the group:

Sender#ping 239.1.2.3 repeat 100000

Type escape sequence to abort.
Sending 100000, 100-byte ICMP Echos to 239.1.2.3, timeout is 2 seconds:

Reply to request 0 from 192.168.10.10, 588 ms
Reply to request 0 from 192.168.11.11, 588 ms
Reply to request 1 from 192.168.10.10, 472 ms
Reply to request 1 from 192.168.11.11, 472 ms
…

As first, SW2 receives the Echo request and sends a PIM-register to the RP (C1), encapsulating the original ICMP packet.

Then, C1 sends a MSDP Source-Active packet to C2: the ICMP packet is encapsulated in the MSDP.

Since C2 has some receivers for the group, it starts forwarding the ICMP packets out FastEthernet0/1 and joins the tree, so that SW1 and SW2 could build the S,G entries.

C2#show ip mroute
IP Multicast Routing Table
[cut]
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.1.2.3), 00:01:13/00:03:15, RP 192.168.1.254, flags: S
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
FastEthernet0/1, Forward/Sparse, 00:01:13/00:03:15

(192.168.20.10, 239.1.2.3), 00:00:14/00:03:22, flags: MT
Incoming interface: FastEthernet0/0, RPF nbr 192.168.0.6
Outgoing interface list:
FastEthernet0/1, Forward/Sparse, 00:00:14/00:03:15

SW1#show ip mroute
IP Multicast Routing Table
[cut]

(*, 239.1.2.3), 00:01:07/stopped, RP 192.168.1.254, flags: SJC
Incoming interface: FastEthernet0/4, RPF nbr 192.168.0.3
Outgoing interface list:
FastEthernet0/2, Forward/Sparse, 00:00:57/00:02:16
FastEthernet0/1, Forward/Sparse, 00:01:07/00:02:11

(192.168.20.10, 239.1.2.3), 00:00:08/00:02:53, flags: JT
Incoming interface: FastEthernet0/4, RPF nbr 192.168.0.3
Outgoing interface list:
FastEthernet0/1, Forward/Sparse, 00:00:08/00:02:51
FastEthernet0/2, Forward/Sparse, 00:00:08/00:02:51

SW2#show ip mroute
IP Multicast Routing Table
[cut]

(*, 239.1.2.3), 00:00:17/stopped, RP 192.168.1.254, flags: SPF
Incoming interface: FastEthernet0/2, RPF nbr 192.168.0.7
Outgoing interface list: Null

(192.168.20.10, 239.1.2.3), 00:00:17/00:03:27, flags: FT
Incoming interface: FastEthernet0/0, RPF nbr 0.0.0.0
Outgoing interface list:
FastEthernet0/2, Forward/Sparse, 00:00:16/00:03:13

You can try to shutdown the link between C2 and SW2 and see how the tree is builded up again around C1 RP.

Topology:

Routers Used: 3640

IOS: c3640-jk9s-mz.124-16.bin

Feature of Topology: Multicast, PIM Sparse-mode, Anycast RP, MSDP

Download: GNS3-Labs: Pierky - Multicasting - PIM Sparse-Mode - Anycast RP-MSDP - IPmc Lab

Tags: Anycast RP, GNS3 Lab and Exercise, GNS3 Topology, MSDP, Multicast, PIM, Sparse mode