Query solicitation (rapid recovery from topology changes) > Why convergence takes so long without query solicitation

When link comes up again

When we reconnect port 1 on the Snooper, the All Groups entry does not reappear.

Manager Switch 2> show igmpsnooping

IGMP Snooping

------------------------------------------------------------------------

Status

Enabled

Disabled All-groups ports

........ None

Vlan Name (vlan id) ..... default (1)

Fast Leave

Off

Query Solicitation

Off

Static Router Ports ..... None

Group List

 

Group. 224.12.13.14

Entry timeout 140 secs

Ports 9

 

------------------------------------------------------------------------

Eventually, the Querier sends an IGMP Query, which the Snooper receives on port 1. This restores the All Groups port on the Snooper. By default the Querier sends General Queries every 125 seconds, so the IGMP convergence delay will be up to 125 seconds with the default settings. For more information about this timeout, see "Configurable IGMP timers and counters" on page 69—but do not change the timeout without very carefully considering the effect on your network.

Manager Switch 2> show igmpsnooping

IGMP Snooping

------------------------------------------------------------------------

Status

...........................

Enabled

Disabled All-groups ports

........ None

Vlan Name (vlan id) ..... default (1)

Fast Leave

Off

Query Solicitation

Off

Static Router Ports ..... None

Group List

 

Group. 224.12.13.14

Entry timeout 107 secs

Ports

9

 

All Groups

Entry timeout 236 secs

Ports

1

 

------------------------------------------------------------------------

When the Snooper receives the General Query, it forwards it out all its ports. The client responds with a Report. The Snooper forwards the Report out its All Groups port towards the Querier. The Querier responds by sending the multicast stream to the Snooper, which forwards the multicast stream out port 9 to the client.

Page 30 AlliedWare™ OS How To Note: IGMP

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Allied Telesis AR400 manual All Groups Entry timeout 236 secs Ports, AlliedWare OS How To Note Igmp