Non-member nodes even on a single subnet do not receive packets (unlike subnet-specific broadcast)
- Non-member nodes even on a single subnet do not receive packets (unlike subnet-specific broadcast)
Group membership on a single subnet is achieved through IGMP (and ICMPv6 in IPv6)
Tree is built by multicast routing protocols. Current multicast tree over the internet is called MBONE.
Anycast: delivers a packet to one of a group (hopefully the closest)