Allied Telesis AR400 User Manual
Allied Telesis Hardware
C613-16087-00 REV C
www.alliedtelesis.com
AlliedWare™ OS
How To |
Introduction
Allied Telesis routers and managed layer 3 switches use IGMP—Internet Group Management
Protocol—to track which multicast groups their clients belong to. This enables them to send
the correct multimedia streams to the correct destination.
This How To Note describes basic and advanced IGMP configuration, in the following major
sections:
z
an overview of IGMP and definitions of some of the IGMP terminology
z
examples and discussion of the most common IGMP functionality—IGMP snooping, IGMP
Querier behaviour and selection, and IGMP proxy
z
examples and discussion of the advanced functionality available through AlliedWare’s
feature-rich IGMP implementation
z
information for debugging
z
information about the STP state of the simple three-switch ring used in most examples
Contents
Messages ............................................................................................................................................. 6
Choosing group addresses ............................................................................................................. 7
Example .............................................................................................................................................. 9
Explanation of IGMP snooping .................................................................................................... 11
Configure IGMP for Multicasting on Routers and
Managed Layer 3 Switches
Document Outline
- Introduction
- IGMP overview
- IGMP snooping
- Multiple potential IGMP queriers
- IGMP proxy
- Query solicitation (rapid recovery from topology changes)
- IGMP filtering (controlling multicast distribution)
- IGMP throttling (limiting the number of streams for each subscriber)
- Static IGMP
- How clients leave groups: queries and timers
- IGMP fast leave
- Configurable IGMP timers and counters
- Example of bad choices for timer values
- Stopping snoopers from snooping non-IGMP messages
- Statically specifying that a port is a router port
- IGMP debugging
- Appendix: STP state