Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 736)

IGMP and IGMP Snooping Introduction
Software Reference for x310 Series Switches
30.10 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
Figure 30-3: Query Solicitation when a port goes down
TC
1. Link to Switch 4
goes down.
Switch 3 stops
blocking and
sends topology
change (TC)
Switch 3 Switch 2: STP root
QS QS
2. Switch 2 receives
TC and sends
Query Solicit (QS)
Switch 2: STP root
QS
GQ GQ
3. Switch 1 receives
QS and sends
General Query (GQ)
GQ
Switch 1: Querier
GQ
Report Report
4. Host receives GQ
and responds with
Membership Report
Report Report
Switch 1: Querier Switch 3 Switch 2: STP root Switch 4
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
igmp_qs