# Configuring PIM SSM

Source Specific Multicast (SSM) is a datagram delivery model that best supports one-to-many applications, also known as broadcast applications. SSM is networking technology that targets audio and video broadcast application environments.

To configure PIM SSM, you enable PIM SSM on the router and define the SSM range of IP multicast addresses.

To use PIM SSM, IGMPv3 must be configured on customer premise equipment (CPE)–facing interfaces to receivers, and PIM sparse mode must be configured on CPE-facing interfaces to sources and on core-facing interfaces. After configuring SSM, you can use the show ip pim sparse-mode sg-state command to display SSM group membership information.

To configure PIM SSM:

1. Enable PIM SSM on the E Series router. The IANA SSM range (232.0.0.0/8) is configured by default. You can modify the SSM address range by using the access list.
   host1(config)#access-list 15 permit ip any host 239.0.0.2 host1(config)#access-list 15 permit ip any 232.0.0.0 0.225.225.225 host1(config)#ip pim ssm range 15
2. Enable PIM sparse mode on the CPE-facing interface towards the source or core.
3. Enable IGMPv3 on the CPE-facing interface towards the receiver. PIM SSM also works with IGMPv2 if you configure the ssm-map in IGMP as in the following example:

PIM SSM also works with IGMPv2 if you configure the ssm-map in IGMP as in the following example:

host1(config)#ip pim ssm host1(config)#access-list ssm_map1 permit 232.0.0.1 255.255.255.255 host1(config)#ip igmp ssm-map enable host1(config)#ip igmp ssm-map static ssm_map1 51.0.0.1

The no version disables ssm-map:

host1(config)#no ip igmp ssm-map static ssm_map1 51.0.0.1

ip pim ssm

- Use to enable PIM SSM and define the SSM range for IPv4 multicast addresses.
- Use the range keyword to define the SSM range of IP multicast addresses.
- Example 1—Enables SSM with addresses in the IANA range. The SSM address range is set as the default and by default, the SSM group multicast address is limited to the IPv4 address range 232.0.0.0/8.
  host1(config)#ip pim ssm
- Example 2—Configures Class D addresses outside of the default SSM range.
  host1(config)#access-list alist permit any 223.0.0.0 0.255.255.255 host1(config)#ip pim ssm range alist
- Example 3—Resets the SSM address range to the default.
  host1(config)#ip pim ssm default
- Use the no version to disable SSM.
- See ip pim ssm.