20
Switch(config)# show ip address
Show the current IP configurations or verify
the configured IP settings.
3. Enable or disable IGMP snooping globally.
IGMP, Internet Group Management Protocol, is a communications protocol used to manage
the membership of Internet Protocol multicast groups. IGMP is used by IP hosts and
adjacent multicast routers to establish multicast group memberships. It can be used for
online streaming video and gaming, and allows more efficient use of resources when
supporting these uses.
IGMP Snooping is the process of listening to IGMP traffic. IGMP snooping, as implied by the
name, is a feature that allows the switch to "listen in" on the IGMP conversation between
hosts and routers by processing the layer 3 packets IGMP packets sent in a multicast
network.
When IGMP snooping is enabled in a switch it analyses all the IGMP packets between hosts
connected to the switch and multicast routers in the network. When a switch hears an IGMP
report from a host for a given multicast group, the switch adds the host's port number to the
multicast list for that group. And, when the switch hears an IGMP Leave, it removes the
host's port from the table entry.
IGMP snooping can very effectively reduce multicast traffic from streaming and other
bandwidth intensive IP applications. A switch using IGMP snooping will only forward
multicast traffic to the hosts interested in that traffic. This reduction of multicast traffic
reduces the packet processing at the switch (at the cost of needing additional memory to
handle the multicast tables) and also reduces the workload at the end hosts since their
network cards (or operating system) will not have to receive and filter all the multicast traffic
generated in the network.
Command / Example
Description
Switch(config)# ip igmp snooping
Enable IGMP snooping function.
No command
Switch(config)# no ip igmp snooping
Disable IGMP snooping function.
Show command
Switch(config)# show ip igmp snooping
Show current IGMP snooping status
including immediate leave function.
Switch(config)# show ip igmp snooping
groups
Show IGMP group table. When IGMP
Snooping is enabled, the Smart Switch is
able to read multicast group IP and the
corresponding MAC address from IGMP
packets that enter the device.
Summary of Contents for HET-2106 SERIES
Page 79: ...79 Restart DHCP service...
