Reference Guide

Related Configuration Tasks
● Use PIM-SSM with IGMP Version 2 Hosts
Enabling PIM-SSM
To enable PIM-SSM, follow these steps.
1. Create an ACL that uses permit rules to specify what range of addresses should use SSM.
CONFIGURATION mode
ip access-list standard name
2. Enter the ip pim ssm-range command and specify the ACL you created.
CONFIGURATION mode
ip pim ssm-range acl-name
To display address ranges in the PIM-SSM range, use the show ip pim ssm-range command from EXEC Privilege mode.
R1(conf)#do show run pim
!
ip pim rp-address 10.11.12.2 group-address 224.0.0.0/4
ip pim ssm-range ssm
R1(conf)#do show run acl
!
ip access-list standard ssm
seq 5 permit host 239.0.0.2
R1(conf)#do show ip pim ssm-range
Group Address / MaskLen
239.0.0.2 / 32
Use PIM-SSM with IGMP Version 2 Hosts
PIM-SSM requires receivers that support IGMP version 3. You can employ PIM-SSM even when receivers support only IGMP
version 1 or version 2 by translating (*,G) entries to (S,G) entries.
Translate (*,G) entries to (S,G) entries using the ip igmp ssm-map acl command source from CONFIGURATION mode. In
a standard access list, specify the groups or the group ranges that you want to map to a source. Then, specify the multicast
source.
● When an SSM map is in place and the system cannot find any matching access lists for a group, it continues to create (*,G)
entries because there is an implicit deny for unspecified groups in the ACL.
● When you remove the mapping configuration, the system removes the corresponding (S,G) states that it created and re-
establishes the original (*,G) states.
● You may enter multiple ssm-map commands for different access lists. You may also enter multiple ssm-map commands for
the same access list, as long as they use different source addresses.
● When an extended ACL is associated with this command, an error message is displayed. If you apply an extended ACL before
you create it, the system accepts the configuration, but when the ACL is later defined, the system ignores the ACL and the
stated mapping has no effect.
To display the source to which a group is mapped, use the show ip igmp ssm-map [group] command. If you use the
group option, the command displays the group-to-source mapping even if the group is not currently in the IGMP group table. If
you do not specify the group option, the display is a list of groups currently in the IGMP group table that has a group-to-source
mapping.
To display the list of sources mapped to a group currently in the IGMP group table, use the show ip igmp groups group
detail command.
PIM Source-Specific Mode (PIM-SSM)
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