Simulating a Multicast Host and Multicast Receiver in a Test Environment , Cisco Routers

Hello All,

I have been training on Multicast for a while now and whenever I start the topic , I find out that my friends /  Colleagues mention that they do not know how to test Multicast Joins. As most of the multicast would be video traffic and they should technically have a whole slew of setup to send and receive some video traffic.

Simple way to do it in a Cisco router is as follows. This applies for all the multicast modes

1. Sparse Mode
2. Dense Mode
3. Sparse-Dense Mode

The below is the topology that I will be using, Please note for the article sake to be more productive , I have chosen emulation with GNS3 itself.

r1--fa0/0-----r5-fa0/1----r4

R1 will be the multicast server, R4 will be the multicast receiver.

What has been assumed in this simulation is :

1. There is an IGP , in this case EIGRP running between r1,r5 and r5
2. There is Pim dense mode (any mode of your choice) running and devices are pim adj

Now, on the server end, in order to generate traffic, a simple Ping can be used as follows:

r1#ping 224.6.7.8 repeat 100
                      
                      Type escape sequence to abort.
                      Sending 100, 100-byte ICMP Echos to 224.6.7.8, timeout is 2 seconds:
                      ..........
                      

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You you will see, the pings are failing, because there isn't a host who wants to receive this traffic. So, how do I make R4 as the host ? Now, by using the below command on any interface of R4 , I will use fa0/1

r4(config)#int fa0/1
                      r4(config-if)#ip igmp join-group 224.6.7.8
                      

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As soon as I do that, I try the ping again, and can now see the response below on R1 again

r1#ping 224.6.7.8 repeat 100
                      
                      Type escape sequence to abort.
                      Sending 100, 100-byte ICMP Echos to 224.6.7.8, timeout is 2 seconds:
                      .......................................................
                      Reply to request 55 from 172.16.45.4, 96 ms
                      Reply to request 56 from 172.16.45.4, 76 ms
                      Reply to request 57 from 172.16.45.4, 52 ms
                      

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This is how you simulate a client and server in your test bed environments or while you are learning this technology without actually having a video server / video clients to receive the actual feeds.

Hope this helps for newbies who wants to learn more and more of this Important technology.

Thank you
Game