Square And Full-Mesh Topology Multicast Guidelines - Avaya 8800 Planning And Engineering, Network Design

Multicast network design
Figure 105: Multicast routing using PIM-SM
Client switches run IGMP Snoop or PIM-SM, and the aggregation switches run PIM-SM. This design
is simple and, for the rest of the network, IP multicast routing is performed by means of PIM-SM.
The aggregation switches are the queriers for IGMP, thus, an external querier is not required to
activate IGMP membership. These switches also act as redundant switches for IP multicast.
Multicast data flows through the IST link when receivers are learned on the client switch and
senders are located on the aggregation switches, or when sourced data comes through the
aggregation switches. This data is destined for potential receivers attached to the other side of the
IST. The data does not reach the client switches through the two aggregation switches because only
the originating switch forwards the data to the client switch receivers.
Note:
Do not place multicast receivers and senders on VLANs that span the IST.

Square and full-mesh topology multicast guidelines

In a square design, you connect a pair of aggregation switches to another pair of aggregation
switches. If you connect the aggregation switches in a full-mesh, it is a full-mesh design. Prior to
release 4.1.1, the full-mesh design did not support SMLT and IP multicast. The current release
supports Layer 3 IP multicast (PIM-SM and PIM-SSM) over a full-mesh SMLT or Routed SMLT
(RSMLT) configuration. The Avaya Ethernet Routing Switch 8800/8600 does not support DVMRP in
SMLT full-mesh designs.
In a square design, you must configure all switches with PIM-SM. Avaya recommends that you
place the BSR and RP in one of the four core switches. For both full-mesh and square topologies
that use multicast, you must set the multicast square-smlt flag.
June 2016 Planning and Engineering — Network Design
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