Technical Tip: PIM SSM (Source-Specific Multicast) configuration guide

[sdabhade]

Description	This article describes how to configure PIM SSM (Source-specific Multicast).
Scope	FortiGate.
Solution	In PIM SSM, the Multicast Receiver Device must be manually configured with the Multicast Source IP and Group IP. PIM SSM must be enabled on all the devices in the Path between the Multicast Source and receiver. config router multicast     set multicast-routing enable         config pim-sm-global             set ssm enable         end   end  IGMPv1/IGMPv2 does not support PIM-SSM, so ensure that IGMPv3 is enabled on the FortiGate interface connected to the Multicast Receiver. Configure 'multicast-flow' for specific Multicast Source IP and group IP from where the receiver is expecting the Multicast Traffic. The Multicast-flow was originally introduced to control acceptable multicast traffic under the FortiGate interface connected to the multicast receiver. static-group configuration under the Interface connected to the Multicast Receivers only applies to cases where there is not any Multicast Receivers that are capable of joining the multicast stream using IGMP. Basically, it is possible to use static-group only in the case there are not any IGMPv3-capable Multicast Receivers or for some other reason, to attract the multicast stream and forward it out on the interface where Multicast Receivers are connected. The FortiGate itself does not become a receiver for the Multicast stream. Sample configuration on FortiGate connected to the Multicast Receiver: config router multicast     set multicast-routing enable         config pim-sm-global             set ssm enable         end         config interface             edit <Interface_Connected_to_Receiver>                 set pim-mode sparse-mode                 set multicast-flow "11"                 set static-group "11"                     config igmp                         set version 3                     end                      next             edit <Backbone_Interface>                 set pim-mode sparse-mode             next         end end config router multicast-flow     edit "11"         config flows             edit 1                 set group-addr <Multicast-Group-IP>                 set source-addr <Multicast-Source-IP>             next         end     next   end