Allied Telesis AR400 - Manual (Page 12)

Page 12 | AlliedWare™ OS How To Note: IGMP
IGMP snooping > Explanation of IGMP snooping
Using Show command output to investigate IGMP state
No group
members
In the first stage of the figure above, the multicast server is turned on and is streaming group
224.12.13.14 to the Querier, switch 1. Switch 1 knows about the group, but has nobody
interested in receiving it. You can see this by using the command show igmpsnooping on
switch 1. The output of this command shows that switch 1 has an entry for the group, but no
associated ports.
Client joins
the group
When a client joins the group, the Group List changes for the Snooper that the client is
attached to, and for the Querier. First, look at the output of the command show
igmpsnooping on the Snooper.
Manager Switch 1> 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 136 secs
Ports None
------------------------------------------------------------------------
Manager Switch 3> 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 257 secs
Ports 3
All Groups Entry timeout 235 secs
Ports 26
------------------------------------------------------------------------