Amer Networks SS2R48G4i V2 - Manual (Page 113)

SS2R24G4i/SS2R48G4i
102
Chapter 11 IGMP Snooping
11.1 Introduction to IGMP Snooping
IGMP (Internet Group Management Protocol) is a protocol used in IP multicast. IGMP is used by
multicast enabled network device (such as a router) for host membership query, and by hosts that are
joining a multicast group to inform the router to accept packets of a certain multicast address. All those
operations are done through IGMP message exchange. The router will use a multicast address
(224.0.0.1) that can address to all hosts to send a IGMP host membership query message. If a host
wants to join a multicast group, it will reply to the multicast address of that a multicast group with a
IGMP host membership reports a message.
IGMP Snooping is also referred to as IGMP listening. The switch prevents multicast traffic from
flooding through IGMP Snooping, multicast traffic is forwarded to ports associated to multicast devices
only. The switch listens to the IGMP messages between the multicast router and hosts, and maintains
multicast group forwarding table based on the listening result, and can then decide to forward multicast
packets according to the forwarding table.
SS2R24/48G4i switch switch provides IGMP Snooping and is able to send a query from the switch
so that the user can use SS2R24/48G4i switch switch in IP multicast.
11.2 IGMP Snooping Configuration
11.2.1 IGMP Snooping Configuration Task
1. Enable IGMP Snooping
2. Configure IGMP Snooping
1.Start IGMP Snooping function
Command Explanation
Global configuration mode
Ip igmp snooping
No ip igmp snooping
Start IGMP Snooping function;the ” No ip
igmp snooping” command will shut down
the IGMP snooping function globally.
2． Configure IGMP Snooping
Command Explanation
Global configuration mode
Ip igmp snooping vlan <vlan-id>
No ip igmp snooping vlan <vlan-id>
Start IGMP Snooping function on the
specified vlan.” No ip igmp snooping vlan
<vlan-id> “ command will disalbe IGMP
function on the sepcified vlan.
Ip igmp snooping vlan < vlan-id > limit Set the max number of the groups IGMP