Configuring Igmp Snooping; Global Configuration And Status - Ubiquiti EdgeSwitch ES-24-250W Administration Manual

EdgeSwitch Administration Guide
™

Configuring IGMP Snooping

Internet Group Management Protocol (IGMP) Snooping is a feature that allows a switch to forward multicast
traffic intelligently on the switch. Multicast IP traffic is traffic that is destined to a host group. Host groups are
identified by class D IP addresses, which range from 224.0.0.0 to 239.255.255.255. Based on the IGMP query
and report messages, the switch forwards traffic only to the ports that request the multicast traffic. This
prevents the switch from broadcasting the traffic to all ports and possibly affecting network performance.
A traditional Ethernet network may be separated into different network segments to prevent placing too
many devices onto the same shared media. Bridges and switches connect these segments. When a packet
with a broadcast or multicast destination address is received, the switch will forward a copy into each of the
remaining network segments in accordance with the IEEE MAC Bridge standard. Eventually, the packet is
made accessible to all nodes connected to the network.
This approach works well for broadcast packets that are intended to be seen or processed by all connected
nodes. In the case of multicast packets, however, this approach could lead to less efficient use of network
bandwidth, especially if the packets are for only a small number of nodes. Packets are flooded into network
segments where no node has any interest in receiving them. While nodes rarely incur any processing
overhead to filter packets addressed to unrequested group addresses, they are unable to transmit new
packets onto the shared media for the period of time that the multicast packet is flooded. The problem of
wasting bandwidth is even worse when the LAN segment is not shared, for example in Full Duplex links.
Allowing switches to snoop IGMP packets is a creative effort to solve this problem. The switch uses the
information in the IGMP packets as they are being forwarded throughout the network to determine which
segments should receive packets directed to the group address.

Global Configuration and Status

Use the IGMP Snooping Global Configuration and Status page to enable IGMP snooping on the switch
and view information about the current IGMP configuration. To access the page, click Switching > IGMP
Snooping > Configuration and Status in the navigation menu.
Field
Admin Mode
Multicast Control Frame Count
Interfaces Enabled for IGMP
Snooping
Data Frames Forwarded by CPU
Use the buttons to perform the following tasks:
• If you make any changes to this page, click Submit to apply the changes.
• Click Refresh to refresh the page with the most current data from the switch.
To retain the changes across the switch's next power cycle, click System > Configuration Storage > Save.
Ubiquiti Networks, Inc.
IGMP Snooping Global Configuration and Status
IGMP Snooping Global Configuration and Status Fields
Description
Select the administrative mode for IGMP Snooping for the switch. The default is Disable.
Shows the number of multicast control frames that have been processed by the CPU.
Lists the interfaces currently enabled for IGMP Snooping. To enable interfaces for IGMP snooping, see
"Interface Configuration" on page 145.
Shows the number of multicast control frames processed by the CPU.
Configuring Switching Information
144