Quick Reference Guide

444 PowerConnect B-Series TI24X Configuration Guide
53-1002269-02
PIM SM traffic snooping overview
18
The following figure shows another example application for PIM SM traffic snooping. This example
shows devices on the edge of a Global Ethernet cloud (a Layer 2 Packet over SONET cloud).
Assume that each device is attached to numerous other devices such as other Layer 2 Switches
and Layer 3 Switches (routers).
NOTE
This example assumes that the devices are actually devices running Layer 2 Switch software.
FIGURE 84 PIM SM traffic reduction in Global Ethernet environment
The devices on the edge of the Global Ethernet cloud are configured for IGMP snooping and PIM
SM traffic snooping. Although this application uses multiple devices, the feature has the same
requirements and works the same way as it does on a single device.
Configuration notes and limitations
• PIM SM snooping applies only to PIM SM version 2 (PIM SM V2).
• PowerConnect B-Series TI24Xdevices support PIM SM traffic snooping in the Layer 2 code.
• IGMP snooping must be enabled on the device that will be running PIM SM snooping. The PIM
SM traffic snooping feature requires IGMP snooping.
Layer 2
Switch B
Layer 2
Switch C
VLAN 2
Port 5
VLAN 2
Port 7
VLAN 2
Port 1
VLAN 2
Port 5
VLAN 2
Port 1
VLAN 2
Port 1
VLAN 2
Port 5
Receiver for Group
239.255.162.69
Client sends an
IGMP group
membership report
for 239.255.162.69.
Receiver for Group
239.255.162.1
Router sends a
PIM SM join message
for 239.255.162.1.
Router
Client
Client
Router
Client
10.10.10.5
Layer 2 switches “snoop” for PIM SM
join and prune messages.
Switch A detects a source on Port 1
and a receiver for the source group on Port5.
Switch forwards multicast data from source on
1 out 5 only, which has the receiver.
Without PIM SM traffic snooping, the switch
forwards traffic from the source out through
all ports.
20.20.20.5
Source for Groups
239.255.162.1
239.255.162.69
Layer 2
Switch A