Summary

In this Chapter, you learned how to design and configure IP Multicast networks using the following multicast infrastructures:

• Internet Standard Multicast (ISM) The ISM model includes protocols for maintaining source state within your network. ISM uses Rendezvous Points to connect receivers to sources. Senders must register with and receivers must join desired groups through the RP. To provide RP redundancy and fault tolerance, you can use the Cisco-developed Auto-RP protocol or the PIMv2 BSR standard protocol. To provide per-group load balancing between RPs, you can enable Anycast RP. With Multicast networks, the network discovers and distributes sources, creating additional load on network devices. For cross-domain source distribution, use MSDP.

• Source Specific Multicast (SSM) With SSM multicast networks, source maintenance is offloaded from the network to the receivers. Last-hop routers join the SPT directly upon receiving IGMPv3 Joins from receivers.

• Reliable Multicast IP Multicast uses UDP as its underlying transport. To provide reliable multicast delivery, you learned how to configure the Cisco IOS PGM Router-Assist feature. This feature provides a guaranteed datagram delivery service to IP Multicast networks by using parallel concepts to TCP, such as datagram sequencing and send-receive windowing. Negative ACKs provide the receiver with a means to request missing datagrams.