Spring 2000John Kristoff1 IP Multicast Computer Networks

Spring 2000John Kristoff2 Recall zUnicast zBroadcast zMulticast ysends to a specific group

Spring 2000John Kristoff3 Introduction to IP Multicast zClass D group address ( x.x.x) yFirst bits must be 1110 of first octet zHow to route to a IP multicast group? zHow to join/leave a multicast group? zHow to map to hardware address?

Spring 2000John Kristoff4 IP Multicast Addressing zSome reserved addresses y RIPv2 routers y organization zIP Multicast to ethernet multicast mapping yplace low-order 23 bits of IP address into low-order 23 bits of special Ethernet address 01:00:5e:00:00:00 yproblem... IP multicast has 28 significant bits!

Spring 2000John Kristoff5 IP Multicast Routing zLimited by scope (TTL) zInternet Group Management Protocol (IGMP) zBased on source address as opposed to destination address zOften based on the familiar tree concept zA rendezvous point (RP) often ties together networks zDVMRP, CBT, PIM-DM, PIM-SM, MOSPF, etc.

Spring 2000John Kristoff6 Internet Mbone zMulticast backbone overlay on the Internet zOriginally used DVMRP, now most use PIM-SM zFew commercial organizations using it zMany educational and research institutions using it