Igmp Layer 2 Querier; Pragmatic General Multicast Guidelines - Avaya 8800 Planning And Engineering, Network Design

MVR is based on IGMP Snoop, but the two features work independently. The MVR VLAN controls
only the VLANs that are bound to it; other IGMP Snoop VLANs operate as usual.
After you enable MVR globally, all IGMP control packages that are received from IGMP Snoop
VLANs that are bound to the MVR VLAN (including report, leave, and query) are processed by
MVR.
If an IGMPv3 snoop interface is used for MVR, both the MVR VLAN and the IGMP Snoop VLANs
must be set to version 3.
For more information about MVR, see Avaya Ethernet Routing Switch 8800/8600 Configuration —
IP Multicast Routing Protocols (NN46205-501).

IGMP Layer 2 querier

In a multicast network, if the multicast traffic only needs to be Layer 2 switched, no multicast routing
is required. However, for multicast traffic to flow from sources to receivers, an IGMP querier must
exist on the network, a function that is normally provided by a multicast router.
To provide a querier on a Layer 2 network without a multicast router, you can use IGMP Layer 2
querier.
The IGMP Layer 2 querier provides the querier functions of a multicast router on the Layer 2
multicast network. The Layer 2 querier forwards queries for multicast traffic, and processes the
responses accordingly. On the connected Layer 2 VLANs, IGMP snoop continues to provide
services as normal, responding to queries and identifying receivers for the multicast traffic.
To enable Layer 2 querier, you must configure an IP address for the querier, in order for it to receive
forwarded report and leave messages.
If a multicast router is present on the network, the Layer 2 querier is automatically disabled.
In the Layer 2 multicast network, enable Layer 2 querier on one of the switches in the VLAN. Only
one Layer 2 querier is supported in the same Layer 2 multicast domain. No querier election is
available.
You cannot enable MVR and Layer 2 querier on the same VLAN.
For more information about IGMP Layer 2 querier, see Avaya Ethernet Routing Switch 8800/8600
Configuration — IP Multicast Routing Protocols (NN46205-501).

Pragmatic General Multicast guidelines

Pragmatic General Multicast (PGM) is a reliable multicast transport protocol for applications that
require ordered, duplicate free, multicast data delivery from multiple sources to multiple receivers.
PGM guarantees that a receiver in a multicast group can receive all data from transmissions and
retransmissions or can detect unrecoverable packet loss.
June 2016 Planning and Engineering — Network Design
Comments on this document? infodev@avaya.com
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