Edge-Core ECS4620-28T Quick Start Manual page 585

meaning that this device will not advertise a QRV in any query messages it
subsequently sends.
◆
Query Interval – Configures the frequency at which host query messages are
sent. (Range: 1-255; Default: 125 seconds)
Multicast routers send host query messages to determine the interfaces that
are connected to downstream hosts requesting a specific multicast service.
Only the designated multicast router for a subnet sends host query messages,
which are addressed to the multicast address 224.0.0.1, and use a time-to-live
(TTL) value of 1.
For IGMP Version 1, the designated router is elected according to the multicast
routing protocol that runs on the LAN. But for IGMP Version 2 and 3, the
designated querier is the lowest IP-addressed multicast router on the subnet.
◆
Query Max Response Time – Configures the maximum response time
advertised in IGMP queries. (Range: 0-255 tenths of a second; Default: 10
seconds)
IGMPv1 does not support a configurable maximum response time for query
messages. It is fixed at 10 seconds for IGMPv1.
By varying the Query Maximum Response Time, the burstiness of IGMP
messages passed on the subnet can be tuned; where larger values make the
traffic less bursty, as host responses are spread out over a larger interval.
The number of seconds represented by the maximum response interval must
be less than the Query Interval.
◆
Last Member Query Interval – The frequency at which to send IGMP group-
specific or IGMPv3 group-source-specific query messages in response to
receiving a group-specific or group-source-specific leave message.
(Range: 1-255 tenths of a second; Default: 1 second)
When the switch receives an IGMPv2 or IGMPv3 leave message from a host that
wants to leave a multicast group, source or channel, it sends a number of
group-specific or group-source-specific query messages as defined by the Last
Member Query Count at intervals defined by the Last Member Query Interval. If
no response is received after this period, the -switch stops forwarding for the
group, source or channel.
◆
Querier – Device currently serving as the IGMP querier for this multicast
service. A querier can only be displayed if IGMP multicasting is enabled, the
VLAN for this entry is up, and is configured with a valid IP address.
Web Interface
To configure IGMP interface settings:
1.
Click Multicast, IGMP, Interface.
2.
Select each interface that will support IGMP (Layer 3), and set the required
IGMP parameters.
Layer 3 IGMP (Query used with Multicast Routing)
– 579 –
Chapter 14
| Multicast Filtering