The following scheme shows the 3 different ways to connect to the M6Bone. Then, each method is described in details, with appropriate generic confirguration examples.

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1 - Equipment with no MRIB support

If the IPv6 unicast and IPv6 multicast topologies are different, you need to setup a router dedicated for IPv6 multicast. On the figure below, the upstream provider of the site does not provide IPv6 multicast and the site setup a tunnel to the M6Bone. As unicast and multicast topologies differ and there is no support of IPv6 multicast routing information base (MRIB), 2 equipments must be used.

The router on the left is the unicast router for the site. It is connected to the IPv6 internet, and advertises on the link the IPv6 prefix. It is the default router for all the hosts on link. The router on the right is the multicast router. It can be for example a PC with FreeBSD that has no IPv6 MRIB support. It is connected to the M6Bone via a tunnel in this example. It does not advertise any prefix and must not route any unicast packet. It is the MLD querier on the link and is in charge of IPv6 multicast only.

Now we take a closer look at routing. The unicast router on the site has a default route to the IPv6 internet (or can use BGP for IPv6 unicast address family). The multicast router has a default route in the tunnel as the IPv6 multicast world is seen from the tunnel.

On the M6Bone POP connecting the site, a static multicast route for the site’s prefix must be configured. This route must be redistributed in MBGP so that the site becomes reachable from all the M6Bone.

In case an IPv6 in IPv6 tunnel is setup. The tunnel end point (in this case the address 2001:660:B101:12::1) must be reachable via the unicast network. Therefore a specific route for this address must be created, the next-hop being the address of the unicast router of the link (2001:660:120A:AB::1)

Configuration example

Unicast router of the site:
ipv6 route ::/0 @C

Multicast router of the site:
ipv6 route ::/0 @B

M6Bone POP:
ipv6 route 2001:660:120A::/48 @A multicast
router bgp 1717
 address family ipv6 multicast
   redistribute static

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2 - Equipment supporting static multicast routes

In this case, a single router in the site can handle the unicast and multicast connections, even if the topologies are different. The MRIB (Multicast Routing Information Base) will be used by PIM to build the multicast tree. The example shown in the figure below represents the case where the ISP of the site does not provide an IPv6 multicast service.

Let’s first consider the unicast topology. The router of the site announces a prefix in the site, being the default router for the workstations on the link. It has a default route toward its ISP (or can use BGP peering).

Regarding the multicast topology, the site’s router has a default multicast route toward the multicast tunnel.

Configuration example

Router of the site:
ipv6 route ::/0 @C
ipv6 route ::/0 @B multicast

M6Bone POP:
ipv6 route site_prefix @A multicast
router bgp 1717
 address family ipv6 multicast
   redistribute static

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3 - Equipment supporting MBGP for IPv6 multicast

The only difference with the previous example is that the MRIB is now populated with MBGP. IPv6 multicast address family of MBGP is used for thi purpose.

The router sets up an MBGP peering with its ISP for the IPv6 unicast address family and sets up another peering with the M6Bone POP for the IPv6 multicast address family.

Configuration example

Router of the site:
router bgp 65000
neighbor @B remote-as 1717
neighbor @C remote-as ???
 address family ipv6 unicast
   neighbor @C activate
   network 2001:660:120A::/48
 address family ipv6 multicast
   neighbor @B activate
   network 2001:660:120A::/48

M6Bone POP:
router bgp 1717
 neighbor @A remote-as 65000
 address family ipv6 multicast
   neighbor @A activate