User guide

Summit24e3 Switch Installation and User Guide 205
17 IP Multicast Routing
This chapter describes the following topics:
• Overview on page 205
• Configuring IP Multicasting Routing on page 206
• Displaying IP Multicast Routing Settings on page 207
• Deleting and Resetting IP Multicast Settings on page 208
For more information on IP multicasting, see the following publications:
• RFC 1112 – Host Extension for IP Multicasting
• RFC 2236 – Internet Group Management Protocol, Version 2
Overview
IP multicast routing is a function that allows a single IP host to send a packet to a group of IP hosts.
This group of hosts can include devices that reside on the local network, within a private network, or
outside of the local network.
IP multicast routing consists of the following functions:
• A router that can forward IP multicast packets.
• A method for the IP host to communicate its multicast group membership to a router (for example,
Internet Group Management Protocol (IGMP)).
NOTE
You should configure IP unicast routing before you configure IP multicast routing.
IGMP Overview
IGMP is a protocol used by an IP host to register its IP multicast group membership with a router.
Periodically, the router queries the multicast group to see if the group is still in use. If the group is still
active, a single IP host responds to the query, and group registration is maintained.