Two types of multicast- 1) Dense mode Multicast 2) Sparse mode Multicast And Explanation of Multicast.

1. Cisco Multicast Routing
With VLC Player
Tapan Doshi

2. Basic Knowledge of Multicast
 What is PIM?
 Protocol Independent Multicast.
 It is a collection of multicast routing protocol each optimized for a different
environment.
 There are mainly Three types:
 1) PIM Sparse Mode
 2) PIM Dense Mode
 3) PIM Sparse-Dense Mode (Bidirectional PIM)

3. How many Types of Multicast?
 Two types of multicast- 1) Dense mode Multicast
2) Sparse mode Multicast
1) Dense mode Multicast:
Dense mode multicast are used for networks where most subnets in your N/W should
receive the multicast traffic. In other words When Router receives the multicast traffic,
it will flood it on all of its interfaces except the interface where it received the traffic
on.
If router is not interested to receive the multicast traffic it will send Prune message
That it should no longer forward the multicast traffic.
Limitation: You will be Wasting a lots of BW and Resources on your Router.

4.  2) Sparse mode multicast:
It will forward the multicast traffic when another router request it , which is complete
opposite to the Dense Mode.
In Network topology you have no idea from where multicast traffic should come from.
To solve out this problem we have defined RP (Rendezvous Point).
All multicast traffic is forwarded to that RP and when another router wants to receive it,
they will have to find their ways towards that RP.
 3) Sparse-Dense Mode Multicast
Sparse-Dense Mode allows the interface to operate on a per-group basis in either Sparse
mode or Dense mode.
A group specified as Dense is not mapped to RP and A group specified as Sparse is
mapped to RP.
It is useful in N/W implementing auto-RP for PIM Sparse mode.
Note: When you enable PIM, it operates in Sparse mode by default.

5.  For real time streaming we are using VLC media server.
 In our topology we have three routers having OSPF with Area 0 (To
Communicate with each other)
 From media Server side we have VLC Stream Server with 239.1.1.1 Multicast
address and it will run on port number 5004.
 Here We are adding TTL value 20 from Server side.
 We have defined R2 Fa 0/0 as RP.
 When Client request for multicast, it will send request to R3’s Fa0/0.
 Therefore we are adding IGMP group of multicast address on another side of R3’s
node (Fa0/1).
 Here We are using Sparse mode and we have defined RP (R2’s Fa0/1).
 Therefore we are adding ip pim rp-address 172.16.1.2 on all of the router.
 We are adding ip igmp join-group 239.1.1.1 command on R3’s Fa0/1 to request
for multicast traffic.
 Finally We have successful reachability for Server to Client.