100
0/2
0/3
0/24
VLANs enabled for IGMP snooping................ 100
VLANs Block enabled for snooping............... None
(QCT) #show igmp snooping querier vlan 100
VLAN 100 : IGMP Snooping querier status
----------------------------------------------
IGMP Snooping Querier VLAN Mode................ Enable
Querier Election Participate Mode.............. Disable
Querier VLAN Address........................... 0.0.0.0
Operational State.............................. Querier
Operational version............................ 2
Operational Max Resp Time...................... 10
After performing the configuration in this example, Host A sends a join message for multicast group
225.1.1.1. Host B sends a join message for group 225.1.1.2. Because IGMP snooping is enabled on the
switch and on VLAN 100, the switch listens to the messages and dynamically adds Ports 1 and 2 to the
multicast address table. Port 3 did not send a join message, so it does not appear in the table, as the
following show command indicates.
(QCT) #show mac-address-table multicast
Fwd
VLAN ID MAC Address Source Type Description Interface Interface
------- ---------------- ------- ------- --------------- --------- ---------
When the video server sends multicast data to group 225.1.1.1, Port 1 participates and receives multicast
traffic, but Port 2 does not participate because it is a member of a different multicast group. Without IGMP
snooping, all ports that are members of VLAN 100 would be flooded with traffic for all multicast groups,
which would greatly increase the amount of traffic on the switch.
3.9.3. IGMPv3/SSM Snooping
IGMPv3 adds support for source filtering, which is the ability for a system to report interest in receiving
packets only from specific source addresses, or from all but specific source addresses sent to a particular
To Next Page
Loading...