Test Out Network Pro: 5.7 Multicast
What is the IP address range reserved for multicast groups?
224.0.0.0 - 239.255.255.255
How does multicast differ from unicast and broadcast?
-With a unicast, messages are sent to a specific host address. The sending device must know the IP address of all recipients, and must create a separate packet for each destination device. -With a broadcast, a single packet is sent to the broadcast address and is processed by all hosts. All hosts, and just group members, receive the packet. Also, broadcast packets are not typically forwarded by routers, so broadcast traffic is limited to within a single subnet.
Which device would you configure to prevent multicast traffic from being sent to non-group members?
A switch capable of Internet Group Management Protocol (IGMP) snooping allows the switch to control which ports get IGMP traffic for a specific group. With IGMP snooping, the switch identifies which ports include members of a specific multicast group. When a message is received for a group, the message is sent only to the ports that have a group member connected.
What does a regular switch do when it receives a multicast frame?
The switch sends the multicast traffic out all ports, because the destination MAC address will be an unknown address. This means that a host might see multicast traffic on its segment, even if it it isn't a member of the group. However, hosts that are not members of the group will not process the frame because they will not associate the multicast MAC address with their own address.
