Non-Rpf Traffic Processing - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Chapter 25 Configuring IPv4 Multicast Layer 3 Switching
A (*,G) state is created on the PIM-RP or for PIM-dense mode but is not used for forwarding the
Note
flows, and Layer 3 switching entries are not created for these flows.

Non-RPF Traffic Processing

These sections describe non-RPF traffic processing:
•
•
•
Non-RPF Traffic Overview
In a redundant configuration where multiple routers connect to the same LAN segment, only one router
forwards the multicast traffic from the source to the receivers on the outgoing interfaces (see
Figure
common VLAN, but the non-PIM DR receives the forwarded multicast traffic. The redundant router
(non-PIM DR) must drop this traffic because it has arrived on the wrong interface and fails the RPF
check. Traffic that fails the RPF check is called non-RPF traffic.
The Catalyst 6500 series switch processes non-RPF traffic in hardware on the PFC3B by filtering
(dropping) or rate limiting the non-RPF traffic.
Figure 25-1
Mulitcast traffic
non-RPF traffic
Filtering of RPF Failures for Stub Networks
The PFC3B supports ACL-based filtering of RPF failures for sparse mode stub networks. When you
enable the ACL-based method of filtering RPF failures by entering the mls ip multicast stub command
on the redundant router, the following ACLs automatically download to the PFC3B and are applied to
the interface you specify:
access-list 100 permit ip A.B.C.0 0.0.0.255 any
access-list 100 permit ip A.B.D.0 0.0.0.255 any
access-list 100 permit ip any 224.0.0.0 0.0.0.255
OL-11439-03
Non-RPF Traffic Overview, page 25-5
Filtering of RPF Failures for Stub Networks, page 25-5
Rate Limiting of RPF Failure Traffic, page 25-6
25-1). In this kind of topology, only the PIM designated router (PIM DR) forwards the data in the
Redundant Multicast Router Configuration in a Stub Network
Rest of network
Router A
Network A, B, C.0
Network A, B, D.0
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
Understanding How IPv4 Multicast Layer 3 Switching Works
Router B
25-5