INS_CWGE10FX2TX8MSPOE 02/19/21 PAGE 57
INSTALLATION AND OPERATION MANUAL
CWGE10FX2TX8MSPOE
TECH SUPPORT: 1.888.678.9427
IGMP Snooping
IGMP Snooping
The IGMP snooping is for multicast traffic. 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. IGMP snooping allows the Switch to learn multicast groups without you
having to manually configure them.
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 4094 VLANs. You can configure the Switch to
automatically learn multicast group membership of any VLANs. The Switch then performs IGMP
snooping on the first 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.
Immediate Leave
When you enable IGMP Immediate-Leave processing, the switch immediately removes a port
when it detects an IGMP version 2 leave message on that port. You should use the Immediate-
Leave feature only when there is a single receiver present on every port in the VLAN. (Immediate
Leave is only supported on IGMP Version 2 hosts).
The switch uses IGMP snooping Immediate Leave to remove from the forwarding table an
interface that sends a leave message without the switch sending group-specific queries to the
interface. The VLAN interface is pruned from the multicast tree for the multicast group specified
in the original leave message. Immediate Leave ensures optimal bandwidth management for all
hosts on a switched network, even when multiple multicast groups are simultaneously in use.
Fast Leave
The switch allow user to configure a delay time. When the delay time is expired, the switch
removes the interface from the multicast group.
Last Member Query Interval