Setting an SSM Group Address Range

The group address range in the Protocol Independent Multicast-Source-Specific Multicast (PIM-SSM) model is different from that in the PIM-SM model. If a multicast group that a user wants to join is within the SSM group address range, the PIM-SSM model is used to forward packets. If a multicast group that a user wants to join is beyond the SSM group address range, the PIM-SM model is used to forward packets. In PIM-SSM model, the default group address range is FF3x::/32. The SSM group address range can be changed as needed.

Context

Ensure that the SSM group address ranges of all routers on an IPv6 network are the same. Otherwise, faults may occur.

Procedure

Run system-view
The system view is displayed.
Configure a basic numbered ACL6 or a naming ACL6 as needed.
- Configure a basic numbered ACL6.
  1. Run acl ipv6 [ number ] basic-acl6-number [ match-order { auto | config } ]
    A basic numbered ACL6 is created, and the basic numbered ACL6 view is displayed.
  2. Run rule [ rule-id ] [ name rule-name ] { deny | permit } [ fragment | source { source-ipv6-address prefix-length | source-ipv6-address/prefix-length | any } ] ^*
    Rules are configured for the basic numbered ACL6.
- Configure a naming ACL6.
  1. Run acl ipv6 name basic-acl6-name basic [ match-order { auto | config } ]
    A naming ACL6 is created, and the naming ACL6 view is displayed.
  2. Run rule [ rule-id ] [ name rule-name ] { deny | permit } [ fragment | source { source-ipv6-address prefix-length | source-ipv6-address/prefix-length | any } ] ^*
    Rules are configured for the naming ACL6.
Run quit
Return to the system view.
Run pim-ipv6
The IPv6 PIM view is displayed.
Run ssm-policy { basic-acl6-number | acl6-name acl6-name }
An SSM group address range is set.
- If a group address matches an ACL rule and the action is permit, the device determines that this group is in the SSM group address range.
- If a group address matches an ACL rule and the action is deny, the device determines that this group is not in the SSM group address range.
- If a group address does not match any ACL rule, the device determines that this group is not in the SSM group address range.
- If a specified ACL does not exist or does not contain rules, the device determines that no groups are in the SSM group address range.
Run commit
The configuration is committed.