Reference Guide
PIM-Sparse Mode (PIM-SM) | 1153
Defaults
Enabled.
Command Modes
CONFIGURATION
Command
History
Usage
Information
By default, when you enable PIM-SM snooping, a switch floods all multicast traffic 
to the PIM designated router (DR), including unnecessary multicast packets. To 
minimize the traffic sent over the network to the designated router, you can disable 
designated-router flooding.
When designated-router flooding is disabled, PIM-SM snooping only forwards the 
multicast traffic, which belongs to a multicast group for which the switch receives a 
join request, on the port connected towards the designated router.
If the PIM DR flood is not disabled (default setting):
• Multicast traffic is transmitted on the egress port towards the PIM DR if the port 
is not the incoming interface.
• Multicast traffic for an unknown group is sent on the port towards the PIM DR. 
When DR flooding is disabled, multicast traffic for an unknown group is 
dropped. 
Related
Commands
show ip pim bsr-router
c e s
View information on the Bootstrap router.
Syntax
show ip pim bsr-router
Command Modes
EXEC
EXEC Privilege
Command
History
Example
E600-7-rpm0#show ip pim bsr-router
PIMv2 Bootstrap information
Version 8.3.19.0 Introduced on S4820T
Version 8.3.12.0 Introduced on the S4810.
Version 8.4.1.1 Introduced on E-Series ExaScale
ip pim snooping Enable PIM-SM snooping.
Version 8.3.19.0 Introduced on S4820T
Version 8.3.7.0 Introduced on S4810 
Version 8.1.1.0 Introduced on E-Series ExaScale
Version 7.8.1.0 Introduced on S-Series










