A client leaves a group – Allied Telesis AR400 User Manual

Page 104

Page 104 | AlliedWare™ OS How To Note: IGMP

IGMP debugging > Example

Client 2 sends a Leave message for group 224.12.13.14. Switch 1 sees the Leave message on
vlan100 (port 49). The port is in a state of “deferred deletion” because of the Last Member
Query process (see

"Last Member Query Count and Last Member Query Interval" on

page 72

Switch 1 is an IGMP Querier, so it sends out two Membership Queries and waits 2 seconds
for a response. None arrives, so switch 1 deletes the entry.

Several minutes later the group entry times out.

Meanwhile, switch 3, which has the client attached to it, sees the same sequence but debugs
it differently. Like switch 1, switch 3 logs the Leave message, but its output also includes the
port on which it received the Leave message. This enables you to identify the client. Switch 3
also logs the two Specific Queries and notes the 2 second timeout. After 2 seconds it also
deletes the entry from its IGMP snooping table.

A client leaves a group

Manager Switch 1> IGMP Snoop(48) on vlan100: Leave -> IGMP Snoop(48): Leave g.

group 224.12.13.14 - Port 49 in deferred deletion.

IGMP Rx(48) on vlan100: Leave -> IGMP Rx(48): Leave group=224.12.13.14 -> group .

Manager Switch 1> IGMP Snoop Timeout: group=224.12.13.14 (0) is deleted

Deleting all ports for group 224.12.13.14 on vlan100

IGMP Timeout: group=224.12.13.14 (0) is deleted

Manager Switch 3> IGMP Snoop: resending pkt to vlan

utPorts: 1-4,6-26 fwdPorts: 26

IGMP Snoop(2) on vlan100: Leave -> IGMP Snoop(2): Leave group=224.12.13.14-> gr.

group 224.12.13.14 - Port 3 in deferred deletion.

IGMP MVR Snoop: discard - no MVR snooper for code 23

IGMP Snoop: resending pkt to vlan

utPorts: 1-4,6-26 fwdPorts: 3,26

IGMP Snoop(25) on vlan100: Query -> code 10

igmpSnoopMembershipQuery >> setting timer at 2 secs

for group 224.12.13.14

snooped group 224.0.0.2 added

Adding port 26 for group 224.0.0.2 on vlan100

IGMP MVR Snoop: discard - no MVR snooper for code 17