Stopping snoopers from snooping non-IGMP messages > Preventing an All Groups entry for a port

Enabling All Groups entry again

To further explore the system we will next reverse the process and follow switch 2 while group entries time out and the switch starts transmitting traffic for the group 224.12.13.14 to the router again. This sequence illustrates the time delay between when you change a port’s All Groups configuration and when multicast traffic flow changes.

1.Permit port 24 to be an All Groups port again.

Manager Switch 2> enable ip igmp allgroups=24

Info (1005003): Operation successful.

2.Check the group entry timeout values.

Manager Switch 2> show igmpsnooping

IGMP Snooping

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

Status

Enabled

Disabled All-groups

ports

........ None

Vlan

Name (vlan id)

..... default (1)

Fast

Leave

Off

Group List

 

No

group memberships.

 

Vlan

Name (vlan id)

..... vlan100 (100)

Fast

Leave

Off

Group

List

 

 

 

Group. 224.12.13.14

Entry timeout

216

secs

Ports

None

 

 

 

All

Groups

Entry timeout

254

secs

Ports

24-25

 

 

 

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

Port 24 is now an All Groups port. However, this not mean that it immediately starts receiving multicast packets for the group 224.12.13.14, as the next few steps show.

3.Reset port 24’s packet counters.

Manager Switch 2> reset switch port=24 counter

Info (1087003): Operation successful.

Page 91 AlliedWare™ OS How To Note: IGMP

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Allied Telesis AR400 manual Enabling All Groups entry again, Permit port 24 to be an All Groups port again