Allied Telesis AR400 - Manual (Page 2)

Page 2 | AlliedWare™ OS How To Note: IGMP
Introduction > Contents
Multiple potential IGMP queriers ...................................................................................................... 15
Example ............................................................................................................................................ 15
Explanation of multiple potential IGMP queriers .................................................................... 17
IGMP proxy ............................................................................................................................................. 21
Example ............................................................................................................................................ 21
Explanation of IGMP proxy .......................................................................................................... 23
Query solicitation (rapid recovery from topology changes) ....................................................... 26
How query solicitation works ..................................................................................................... 26
Why convergence takes so long without query solicitation ................................................ 28
Speeding up IGMP convergence in a non-looped topology ................................................. 33
Enabling query solicitation on multiple switches in a looped topology ............................. 33
IGMP filtering (controlling multicast distribution) ......................................................................... 35
Example ............................................................................................................................................ 35
Explanation of IGMP filtering (controlling multicast distribution) ...................................... 38
IGMP throttling (limiting the number of streams for each subscriber) .................................... 40
Example ............................................................................................................................................ 40
Explanation of IGMP throttling (limiting the number of streams for each subscriber) . 43
Static IGMP ............................................................................................................................................. 48
Example ............................................................................................................................................ 48
Explanation of
Static IGMP .......................................................................................................... 51
How clients leave groups: queries and timers ................................................................................ 58
Overview of leave process ........................................................................................................... 58
Querier timer values ..................................................................................................................... 58
Snooper timer values .................................................................................................................... 59
Comparing the Querier and Snooper timers .......................................................................... 60
Consequences for high-loss and high-lag networks ............................................................... 60
IGMP fast leave ....................................................................................................................................... 61
Example ............................................................................................................................................ 61
Explanation of IGMP fast leave .................................................................................................... 63
Configurable IGMP timers and counters ......................................................................................... 69
Timer and counter relationships ................................................................................................ 69
Software versions ........................................................................................................................... 70
Initial configuration ........................................................................................................................ 70
Default values .................................................................................................................................. 72
Last Member Query Count and Last Member Query Interval ........................................... 72
Robustness Variable ....................................................................................................................... 75
Default Query Interval ................................................................................................................. 76
Query Response Interval ............................................................................................................. 77
Default Timeout Interval .............................................................................................................. 78
Example of bad choices for timer values ......................................................................................... 83
Example ............................................................................................................................................ 83
Problem 1: Last Member Query Interval too short .............................................................. 84
Problem 2: Query Response Interval short ............................................................................. 84
Problem 3: Default Timeout Interval too short ..................................................................... 84