Data link layer multicasting

[aguila3380]

You have 4 computers in a LAN segment PC-A,PC-B,PC-C, and PC-D, and PC's A,C, and D, are part of the same multicast group. If PC-A sends out a multicast, how is PC-B going to know to drop the packet because it does not belong to PC's A,C,and D's dynamically elected multicast group? Wouldn't a multicast address still look like a broadcast address (FFFF.FFFF.FFFF) where PC-B could not tell the difference?

PS. If you have the chance, later could you e-mail me on the mechanics of how a multicast group is dynamically elected. my e-mail is smashhead2004@yahoo.com.

thank you!

[jon.tucker]

A multicast address is not the same as a broadcast address. IGMP Snooping or CGMP will allow you to tune your multicast traffic efficiently on your network. The book Developing IP Multicast Networks (Cisco Press) is a good read if you want a good study source. The Cisco Multicast support page is here: http://www.cisco.com/en/US/tech/tk828/tsd_technology_support_protocol_home.html