ip mroute (PIM-SM)

ip mroute|

Description

Configures multicast reverse path (RPF) forwarding static routes. This command is an alias of therpf-overridecommand.

Parameter	Description
	Specifies the multicast source address in IPv4 format (x.x.x.x), wherexis a decimal number from 0 to 255.
	Specifies the number of bits in the address mask in CIDR format (x), wherexis a decimal number from 0 to 128.
	Specifies the RPF address in IPv4 format (x.x.x.x), wherexis a decimal number from 0 to 255.
	Specifies the RPF interface name.

Usage

Reverse Path Forward (RPF) checking is a core multicast routing mechanism. The RPF ensures that the multicast traffic received arrives on the expected router interface before further processing. If the RPF check fails for a multicast packet, the packet is discarded. For multicast traffic flow that arrives on the SPT, the expected incoming interface for a given source or group is the interface towards the source address of the traffic (determined by the unicast routing system). For traffic arriving on the RP tree, the expected incoming interface is the interface towards the RP.

RPF checking is applied to all multicast traffic and is significant in preventing network loops. Up to eight manual RPF overrides can be specified. The RPF-address indicates one of two distinct RPF candidates:

The RPF-address indicates one of two distinct RPF candidates:

1. A valid PIM neighbor address from which forwarded multicast traffic is accepted with a source address of. A valid PIM neighbor with should exists and mandatory for RPF-address option to work. PIM join will be sent towards that next-hop and data traffic will be forwaded from the upstream links. rpf-override may not work in absence of valid PIM neighbor. An alias CLI command 'ip mroute' to 'rpf-override' configuration command described in below section can also be used alternatively.
2. A local PIM-enabled interface to which is directly connected. With this entry the local router will treat the flow as directly connected and route it if there are any joins. Interface name is typically used when a source from different subnet is directly connected to the given interface. The normal RPF lookup would otherwise fail for this and won't route it. Since the RPF entry doesn't point to any specific PIM neighbor under the interface, PIM will not send join towards upstream. So it must be noted that this option will work only when the source traffic is directly connected on same router where it is configured.

Example

Configuring and removing an IP mroute:

Configuring andremoving an IP mroute for an IPv6 address:

Command History

Release	Modification
10.10	Command introduced

Command Information

Platforms	Command context	Authority
8400 9300	Operator (>) or Manager (#)	Operators or Administrators or local user group members with execution rights for this command. Operators can execute this command from the operator context (>) only.