Multicast; Chapter 24 Multicast; Multicast Overview; What You Can Do - ZyXEL Communications XS1930-12HP User Manual

24.1 Multicast Overview

This chapter shows you how to configure various multicast features.
Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender to 1 recipient) or
Broadcast (1 sender to everybody on the network). Multicast delivers IP packets to just a group of hosts
on the network.
IGMP (Internet Group Management Protocol) is a network-layer protocol used to establish membership
in a multicast group - it is not used to carry user data. Refer to RFC 1112, RFC 2236 and RFC 3376 for
information on IGMP versions 1, 2 and 3 respectively.

24.1.1 What You Can Do

• Use the Multicast Setup screen
screens where you can configure IPv4 or IPv6 multicast settings.
• Use the IPv4 Multicast Status screen
• Use the IGMP Snooping screen
group multicast traffic only to ports that are members of that group.
• Use the IGMP Snooping VLAN screen
16 VLANs.
• Use the IGMP Filtering Profile
clients connected to the Switch are able to join.

24.1.2 What You Need to Know

Read on for concepts on Multicasting that can help you configure the screens in this chapter.
IP Multicast Addresses
In IPv4, a multicast address allows a device to send packets to a specific group of hosts (multicast
group) in a different subnetwork. A multicast IP address represents a traffic receiving group, not
individual receiving devices. IP addresses in the Class D range (224.0.0.0 to 239.255.255.255) are used for
IP multicasting. Certain IP multicast numbers are reserved by IANA for special purposes (see the IANA
website for more information).
IGMP Snooping
A Switch can passively snoop on IGMP packets transferred between IP multicast routers/switches and IP
multicast hosts to learn the IP multicast group membership. It checks IGMP packets passing through it,
picks out the group registration information, and configures multicasting accordingly. IGMP snooping
allows the Switch to learn multicast groups without you having to manually configure them.
C
(Section 24.2 on page
(Section 24.3 on page
(Section 24.3.1 on page
(Section 24.3.2 on page
(Section 24.3.3 on page
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H A P T E R

Multicast

196) to display the links to the configuration
196) to view multicast group information.
197) to enable IGMP snooping to forward
200) to perform IGMP snooping on up to
201) to specify a range of multicast groups that
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