Chapter 11 IPsec VPN for FortiOS 5.0 : IPv6 Configuration : IPv6 PIM sparse mode multicast routing
  
IPv6 PIM sparse mode multicast routing
FortiOS supports PIM sparse mode multicast routing for IPv6 multicast (multicast6) traffic and is compliant with RFC 4601. You can use the following command to configure IPv6 PIM sparse multicast routing.
config router multicast6
set multicast-routing {enable | disable}
config interface
edit <interface-name>
set hello-interval <1-65535 seconds>
set hello-holdtime <1-65535 seconds>
end
config pim-sm-global
config rp-address
edit <index>
set ipv6-address <ipv6-address>
end
The following diagnose commands for IPv6 PIM sparse mode are also available:
diagnose ipv6 multicast status
diagnose ipv6 multicast vif
diagnose ipv6 multicast mroute