Igmp Snooping; Igmp Querier; Querier Election - Lenovo RackSwitch G8264 Application Manual

IGMP Snooping

IGMP Querier

Querier Election

1. Enable IGMP and configure the source IPv4 address for IGMP Querier on a VLAN.
2. Enable IGMP Querier on the VLAN.
3. Configure the querier election type and define the address.
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G8264 Application Guide for ENOS 8.4
IGMP Snooping allows a switch to listen to the IGMP conversation between hosts
and Mrouters. By default, a switch floods multicast traffic to all ports in a
broadcast domain. With IGMP Snooping enabled, the switch learns the ports
interested in receiving multicast data and forwards it only to those ports. IGMP
Snooping conserves network resources.
The switch can sense IGMP Membership Reports from attached hosts and acts as a
proxy to set up a dedicated path between the requesting host and a local IPv4
Mrouter. After the path is established, the switch blocks the IPv4 multicast stream
from flowing through any port that does not connect to a host member, thus
conserving bandwidth.
For IGMP Snooping to function, you must have an Mrouter on the network that
generates IGMP Query packets. Enabling the IGMP Querier feature on the switch
allows it to participate in the Querier election process. If the switch is elected as the
Querier, it will send IGMP Query packets for the LAN segment.
If multiple Mrouters exist on the network, only one can be elected as a Querier. The
Mrouters elect the one with the lowest source IPv4 address or MAC address as the
Querier. The Querier performs all periodic membership queries. All other
Mrouters (non‐Queriers) do not send IGMP Query packets.
Note: When IGMP Querier is enabled on a VLAN, the switch performs the role of
an IGMP Querier only if it meets the IGMP Querier election criteria.
Each time the Querier switch sends an IGMP Query packet, it initializes a general
query timer. If a Querier receives a General Query packet from an Mrouter with a
lower IP address or MAC address, it transitions to a non‐Querier state and
initializes an other querier present timer. When this timer expires, the Mrouter
transitions back to the Querier state and sends a General Query packet.
Follow this procedure to configure IGMP Querier.
RS G8264(config)# ip igmp enable
RS G8264(config)# ip igmp querier vlan 2 source­ip 10.10.10.1
RS G8264(config)# ip igmp querier vlan 2 enable
RS G8264(config)# ip igmp querier vlan 2 election­type ipv4