Large IPv6 Multicast Domains

Benedikt Stockebrand bs at
Thu Jun 5 11:14:37 CEST 2014

Hi Jim and list,

first off, I've done some IPv6 multicast routing but I've never been
unlucky enough not to deal with it over IPv4.

> 1)      There is no MSDPv6 and probably never will be.  Of course you
> have SSM and Embedded RP but that doesn’t cover all cases.  For
> example – if you have a partnership with another organization and only
> want to share select multicast groups/sources then in IPv4 you use
> MSDP and MSDP filters.  However, I don’t see how to do this with IPv6
> multicast.

Would it work if you used one of the available (unnamed) scopes for that
job?  Agree on a scope that gets routed with your partner organization
and set up your border multicast routers accordingly.

> 2)      Often I see different multicast domains with MSDP between them
> (including filters).  Do organizations just do one huge PIMv6-Anycast
> domain and leave it at that?

I'm not sure what you mean with "PIMv6-Anycast domain", but if I
understand your question correctly, then the answer is yes: One
(possibly anycasted) RP or set of RPs for all "multicast domains" (which
is a concept that doesn't really apply to IPv6) and matching scopes to
filter between the domains.  (And yes, there may be constellations where
you actually run out of scopes...)

If there is no direct connection between the domains, either use some
sort of VPN (which you'll likely have anyway) or possibly just a simple
GRE or configured 6in4 tunnel.



Benedikt Stockebrand,                   Stepladder IT Training+Consulting

          Business Grade IPv6 --- Consulting, Training, Projects

BIVBlog---Benedikt's IT Video Blog:

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