Cisco 7604 Configuration Manual page 477

Configuring PIM Snooping
This chapter describes how to configure protocol independent multicast (PIM) snooping on the
Cisco 7600 series routers. Release 12.2(17a)SX and later releases support PIM snooping.
For complete syntax and usage information for the commands used in this chapter, refer to the Cisco IOS
Note
Master Command List, Release 12.2SX at this URL:
http://www.cisco.com/en/US/docs/ios/mcl/122sxmcl/12_2sx_mcl_book.html
This chapter consists of these sections:
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For additional information (including configuration examples and troubleshooting information), see the
Tip
documents listed on this page:
http://www.cisco.com/en/US/products/hw/routers/ps368/tsd_products_support_series_home.html
Understanding How PIM Snooping Works
In networks where a Layer 2 router interconnects several routers, such as an Internet exchange point
(IXP), the router floods IP multicast packets on all multicast router ports by default, even if there are no
multicast receivers downstream. With PIM snooping enabled, the router restricts multicast packets for
each IP multicast group to only those multicast router ports that have downstream receivers joined to that
group. When you enable PIM snooping, the router learns which multicast router ports need to receive
the multicast traffic within a specific VLAN by listening to the PIM hello messages, PIM join and prune
messages, and bidirectional PIM designated forwarder-election messages.
OL-4266-08
Understanding How PIM Snooping Works, page 31-1
Default PIM Snooping Configuration, page 31-4
PIM Snooping Configuration Guidelines and Restrictions, page 31-4
Configuring PIM Snooping, page 31-5
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
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