User Manual

24-Port and 48-Port Gigabit Ethernet PoE+ Smart Switches with 4 SFP Ports
Configure Switching User Manual229
The following table describes the nonconfigurable information displayed on the page.
Table 47. Querier VLAN Status information
Field Description
VLAN ID The VLAN ID on which IGMP snooping querier is administratively enabled
and the VLAN exists in the VLAN database.
Operational State The operational state of the IGMP snooping querier on a VLAN. It can be in
any of the following states:
Operational Version The operational IGMP protocol version of the querier.
Last Querier Address The IP address of the last querier from which a query was snooped on the
VLAN.
Last Querier Version The IGMP protocol version of the last querier from which a query was
snooped on the VLAN.
Operational Max Response Time The maximum response time to be used in the queries that are sent by the
snooping querier
.
Manage MLD snooping
In IPv6 networks, Multicast Listener Discovery (MLD) snooping performs a similar function as
IGMP does in IPv4 networks. With MLD snooping, IPv6 multicast data is selectively
forwarded to ports that are configured to receive the data, instead of being flooded to all ports
in a VLAN. The ports are determined by snooping IPv6 multicast control packets.
A multicast listener is a device that is configured to receive IPv6 multicast packets. MLD is
used by IPv6 multicast routers to discover the presence of multicast listeners on its
directly-attached links and to discover which multicast packets are of interest to neighboring
devices.
The MLD protocol is derived from IGMP. MLD version 1 (MLDv1) is equivalent to IGMPv2,
and MLD version 2 (MLDv2) is equivalent to IGMPv3. MLD is a subprotocol of Internet
Control Message Protocol version 6 (ICMPv6), and MLD messages are a subset of ICMPv6
messages, identified in IPv6 packets by a preceding Next Header value of 58.
• Querier. The snooping switch is the querier in the VLAN. The snooping
switch sends out periodic queries with a time interval equal to the
configured querier query interval. If the snooping switch finds a better
querier in the VLAN, it moves to non-querier mode.
• Non-Querier. The snooping switch is in non-querier mode in the VLAN.
If the querier expiry interval timer expires, the snooping switch moves
into querier mode.
• Disabled. The snooping querier is not operational on the VLAN. The
snooping querier moves to disabled mode when IGMP snooping is not
operational on the VLAN or when the querier address is not configured
or the network management address is also not configured.