ssm-enable

Enables Source Specific Multicast (SSM) mode for IPv4 PIM.

Syntax

ssm-enable range prefix-list

no ssm-enable range prefix-list

Command Default

By default, PIM-SSM is not enabled.

Parameters

range: Specifies the range of the SSM map. By default, the range is 232.0.0.0/8 for IPv4.
prefix-list: Specifies the IPv4 prefix list that identifies the multicast group address range.

Modes

Router PIM configuration mode

Usage Guidelines

PIM-SSM is a subset of the PIM-SM protocol. In PIM-SSM mode, the Shortest Path Tree (SPT) is created at the source. The router closest to the receiver host is notified of the unicast IP address of the source for the multicast traffic. PIM-SSM goes directly to the source-based distribution tree without the need of the RP connection. In contrast to PIM-SM, PIM-SSM forms its own SPT, without forming a shared tree.

Examples

The following example enables SSM and applies the default IPv4 SSM range of 232.0.0.0/8.

device(config)# router pim
device(config-pim-router)# ssm-enable

The following example enables SSM and configures an SSM map at the global level.

device(config)# ip igmp ssm-map enable
device(config)# ip igmp ssm-map ssm-map-230-to-232 203.0.0.10
device(config)# ip igmp ssm-map ssm-map-233-to-234 204.0.0.10

The following example configures the SSM range at the router PIM configuration level.

device(config)# router pim
device(config-pim-router)# ssm-enable range PL_ssm_range-230-to-234