ZyXEL Communications 4528F Manual De Usuario

Chapter 24 Multicast

XGS-4526/4528F/4728F User’s Guide

The 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.

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.

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. 

Click Advanced Applications > Multicast to display the screen as shown. This 
screen shows the multicast group information. See 

 for 

more information on multicasting.

Figure 98   Advanced Application > Multicast 

The following table describes the labels in this screen. 

Table 62   Multicast Status 

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.