Cisco 7604 Configuration Manual page 424

IPv4 Multicast Layer 3 Switching Configuration Guidelines and Restrictions
Table 28-1 Default IP Multicast Layer 3 Switching Configuration
Feature
ACL for stub networks
Installing of directly connected subnet entries
Multicast routing
PIM routing
IP multicast Layer 3 switching
Shortcut consistency checking
Internet Group Management Protocol (IGMP) snooping is enabled by default on all VLAN interfaces. If
you disable IGMP snooping on an interface, multicast Layer 3 flows are still switched by the hardware.
Bridging of the flow on an interface with IGMP snooping disabled causes flooding to all forwarding
interfaces of the VLAN. For details on configuring IGMP snooping, see
Snooping for IPv4 Multicast Traffic."
IPv4 Multicast Layer 3 Switching Configuration Guidelines and
Restrictions
These sections describe IP Multicast Layer 3 switching configuration restrictions:
•
•
Restrictions
IP multicast Layer 3 switching is not provided for an IP multicast flow in the following situations:
•
•
•
•
•
•
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
28-8
Restrictions, page 28-8
Unsupported Features, page 28-9
For IP multicast groups that fall into the range 224.0.0.* (where * is in the range 0 to 255), which
is used by routing protocols. Layer 3 switching is supported for groups 224.0.2.* to 239.*.*.*.
Groups in the 224.0.0.* range are reserved for routing control packets and must be flooded
Note
to all forwarding ports of the VLAN. These addresses map to the multicast MAC address
range 01-00-5E-00-00-xx, where xx is in the range 0–0xFF.
For PIM auto-RP multicast groups (IP multicast group addresses 224.0.1.39 and 224.0.1.40).
For packets with IP options. However, packets in the flow that do not specify IP options are hardware
switched.
For source traffic received on tunnel interfaces (such as MBONE traffic).
If a (S,G) entry for sparse mode does not have the SPT-bit, RPT-bit, or Pruned flag set.
A (*,G) entry is not hardware switched if at least one (S,G) entry has an RPF different from the (*,G)
entry's RPF and the (S,G) is not hardware switched.
Chapter 28 Configuring IPv4 Multicast Layer 3 Switching
Default Value
Disabled on all interfaces
Enabled globally
Disabled globally
Disabled on all interfaces
Enabled when multicast routing is enabled and PIM
is enabled on the interface
Enabled
Chapter 30, "Configuring IGMP
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