Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 738)

IGMP and IGMP Snooping Introduction
Software Reference for x310 Series Switches
30.12 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
Figure 30-4: Packet flow for a four switch network with Query Solicitation enabled
Switch 1: Querier Switch 3 Switch 2: STP root
Initial state:
Port on switch 3
is blocking.
Multicasts flow
from server to
client via switches
1 and 4
Multicast
Multicast
Multicast
Multicast Multicast
Switch 1: Querier Switch 3 Switch 2: STP root Switch 4
Final state:
Multicasts flow
from server to
client via Switches
1, 2, 3, and 4
Multicast Multicast Multicast
QS from 3
1. Link to switch 4
goes down.
Switch 3 stops
blocking and
sends Topology
Change (TC) and
Query Solicit (QS).
Switch 2 forwards
QS to switch 1.
Switch 1 sends
General Query (GQ)
Switch 3 Switch 2: STP root Switch 4
TC from 3
QS from 3
GQ from 1 GQ from 1 GQ from 1 GQ from 1
TC from 3
Switch 1: Querier
2. Switch 2 receives TC
from switch 3.
Switch 2 sends QS.
to switch 1.
Switch 1 sends GQ
Switch 3 Switch 2: STP root Switch 4
QS from 2
GQ from 1 GQ from 1 GQ from 1 GQ from 1
Switch 1: Querier
QS from 4
3. Switch 4 receives TC
from switch 3.
Switch 4 sends QS.
towards switch 1.
Switch 1 sends GQ
Switch 3 Switch 2: STP root Switch 4
QS from 4
GQ from 1 GQ from 1 GQ from 1 GQ from 1
Switch 1: Querier
QS from 4
4. Client replies to each
GQ by sending
Membership Reports
Switch 3 Switch 2: STP root Switch 4 Switch 1: Querier
Report Report Report Report
Report Report Report Report
Report Report Report Report
igmp_qs_multiple