Igmp Snooping; Igmp Snooping And Vlans; Multicast Status - ZyXEL Communications MS-7206 - EDITION 1 Manual

Chapter 27 Multicast

27.1.3 IGMP Snooping

A switch can passively snoop on IGMP Query, Report and Leave (IGMP version 2)
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.
The switch forwards multicast traffic destined for multicast groups (that it has
learned from IGMP snooping or that you have manually configured) to ports that
are members of that group. IGMP snooping generates no additional network
traffic, allowing you to significantly reduce multicast traffic passing through your
switch.

27.1.4 IGMP Snooping and VLANs

The switch can perform IGMP snooping on up to 16 VLANs. You can configure the
switch to automatically learn multicast group membership of any VLANs. The
switch then performs IGMP snooping on the first 16 VLANs that send IGMP
packets. This is referred to as auto mode. Alternatively, you can specify the VLANs
that IGMP snooping should be performed on. This is referred to as fixed mode. In
fixed mode the switch does not learn multicast group membership of any VLANs
other than those explicitly added as an IGMP snooping VLAN.

27.2 Multicast Status

Use this screen to look at current multicast groups. See
for background information about multicasting. To open this screen, click
Advanced Application > Multicast.
Figure 72 Multicast Status
The following table describes the labels in this screen.
Table 54 Multicast Status
LABEL
Index
VID
180
DESCRIPTION
This is the index number of the entry.
This field displays the multicast VLAN ID.
Section 27.1 on page 179
MS-7206 User's Guide