Design Reference
Table Of Contents
- Contents
- Chapter 1: Introduction
- Chapter 2: New in this release
- Chapter 3: Network design fundamentals
- Chapter 4: Hardware fundamentals and guidelines
- Chapter 5: Optical routing design
- Chapter 6: Platform redundancy
- Chapter 7: Link redundancy
- Chapter 8: Layer 2 loop prevention
- Chapter 9: Spanning tree
- Chapter 10: Layer 3 network design
- Chapter 11: SPBM design guidelines
- Chapter 12: IP multicast network design
- Multicast and VRF-lite
- Multicast and MultiLink Trunking considerations
- Multicast scalability design rules
- IP multicast address range restrictions
- Multicast MAC address mapping considerations
- Dynamic multicast configuration changes
- IGMPv3 backward compatibility
- IGMP Layer 2 Querier
- TTL in IP multicast packets
- Multicast MAC filtering
- Guidelines for multicast access policies
- Multicast for multimedia
- Chapter 13: System and network stability and security
- Chapter 14: QoS design guidelines
- Chapter 15: Layer 1, 2, and 3 design examples
- Chapter 16: Software scaling capabilities
- Chapter 17: Supported standards, RFCs, and MIBs
- Glossary
Note:
If you enable the explicit host tracking option on an IGMPv3 interface, you cannot downgrade
to IGMPv1 or IGMPv2. You must disable explicit host tracking to downgrade the IGMP
version.
IGMP Layer 2 Querier
In a multicast network, if you only need to use Layer 2 switching for the multicast traffic, you
do not need multicast routing. However, you must have an IGMP querier on the network for
multicast traffic to flow from sources to receivers. A multicast router normally provides the IGMP
querier function. You can use the IGMP Layer 2 Querier to provide a querier on a Layer 2
network without a multicast router.
The Layer 2 querier function originates queries for multicast receivers, and processes the
responses accordingly. On the connected Layer 2 VLANs, IGMP snoop continues to provide
services as normal. IGMP snoop responds to queries and identifies receivers for the multicast
traffic.
You must enable Layer 2 querier and configure an IP address for the querier before it can
originate IGMP query messages. If a multicast router exists on the network, Virtual Services
Platform 4000 automatically disables the Layer 2 querier.
In a Layer 2 multicast network, enable Layer 2 querier on only one of the switches in the VLAN.
A Layer 2 multicast domain supports only one Layer 2 querier. No querier election exists.
For more information about how to configure IGMP Layer 2 Querier, see Avaya Virtual Services
Platform 4000 Configuration — IP Multicast Routing Protocols, NN46251–504.
TTL in IP multicast packets
Virtual Services Platform 4000 treats multicast data packets with a time-to-live (TTL) of 1 as
expired packets and sends them to the CPU before dropping them. To avoid this, ensure that
the originating application uses a hop count large enough to enable the multicast stream to
traverse the network and reach all destinations without reaching a TTL of 1. Avaya
recommends that you use a TTL value of 33 or 34 to minimize the effect of looping in an
unstable network.
IGMP Layer 2 Querier
Network Design Reference for Avaya VSP 4000 February 2014 113