I spent all day yesterday and half day today working the Multicast labs from Volume 5 NB WB. I must say that these will walk you through from Dense-mode to Sparse-Mode. Then Narbik will let you configure static RP, Auto RP and RP Filtering brings this section to an end. There were tons of “gotchas” but I was able to stumble my way through the labs. As others have pointed out, Multicast is not difficult. Fact of the matter is that we are not used to multicast. Almost everyone of us works with unicast routing all day long. With that said, I think reading a few white papers on multicast will definitely help. I ordered a multicast book today so I can read it while on the plane to Pasadena next week.
As I did with previous section, I won’t have my notes up because I am running out of time. I found this great Q&A on multicast so I will let you guys read that and I am going to start my favorite section aka QoS!
Q—What is the range of available IP multicast addresses?
A—224.0.0.0 to 239.255.255.255.
Q—What is the purpose of IGMP?
A—IGMP is used between the hosts and their local multicast router to join and leave multicast groups.
Q—What is an advantage of IGMPv2 over IGMPv1?
A—IGMPv2 has a leave group message that can greatly reduce the latency of unwanted traffic on a LAN.
Q—What is a potential disadvantage of IGMP snooping over CGMP on a low-end Layer 2 switch?
A—IGMP snooping requires the switch to examine every multicast packet for an IGMP control message. On a low-end switch, this might have a severe performance impact.
Q—What is an advantage of shortest path (or source) trees compared to shared trees?
A—Source trees guarantee an optimal path between each source and each receiver, which will minimize network latency.
Q—What is an advantage of using shared trees?
A—Shared trees require very little state to be kept in the routers, which requires less memory.
Q—What information does the router use to do an RPF check?
A—The unicast routing table.
Q—Why is protocol-independent multicast called “independent”?
A—PIM works with any underlying IP unicast routing protocol—RIP, EIGRP, OSPF, BGP or static routes.
Q—What is the main advantage of MBGP?
A—Providers can have noncongruent unicast and multicast routing topologies.
Q—How do RPs learn about sources from other RPs with MSDP?
A—RPs are configured to be MSDP peers with other RPs. Each RP forwards source active (SA) messages to each other.
Q—What is the purpose of the anycast RP?
A—Load balancing and fault tolerance.
About CCIETalk
hehe…. my whole day at work today was trying to re-create a multicast issue that we have in production… trying to re-create the problem in the lab has really shown me that multicast can be difficult
LOL.
Multicast can be a pain. I ran into some issues last year when I deployed this multicast callcenter application @ work. It was a pain but once I got it working, it was a dream!