ZyXEL Communications ES-2048, User Manual

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Chapter 19 Multicast
ES-2048 User’s Guide
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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.
19.1.4 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.
19.2 Multicast Status
Click Advanced Applications > Multicast to display the screen as shown. This screen shows
the multicast group information. See Section 19.1 on page 143 for more information on
multicasting.
Figure 69 Advanced Application > Multicast
The following table describes the labels in this screen.
19.3 Multicast Setting
Click Advanced Applications > Multicast > Multicast Setting link to display the screen as
shown. See Section 19.1 on page 143 for more information on multicasting.
Table 42 Advanced Application > Multicast Status
LABEL DESCRIPTION
Index This is the index number of the entry.
VID This field displays the multicast VLAN ID.
Port This field displays the port number that belongs to the multicast group.
Multicast Group This field displays IP multicast group addresses.