All things related to multicast

[John Kristoff <>]

I wonder if anyone can provide further info on the following, that
would be helpful.

224.0.1.20 - any private experiment

  I'm seeing a few of these and while I don't really care what they
  are, I'm curious if 'private' means some type of scoping is
  appropriate for this address.  I see RFC 3648, an experimental
  protocol, uses this address, as suggested by the IESG, for
  flooding on what I believe are local links.  Perhaps I'm seeing
  leaks from experiments with that protocol?  I see some network
  operators are already filtering this group address.

224.0.1.41 - gatekeeper

  I guess if you're doing some type of VoIP service you may want
  to generally scope these so prevent clients from connecting to
  other gatekeepers and from others connecting to your's, but is
  that a universal truth?  Are there public gatekeepers that are
  intended to be reachable via this group address?

224.0.1.0/24 - internetwork control block

  Is there that much in this block that cannot be scoped at public
  Internet to private internetwork boundaries?  The IETF audio and
  video plus mtrace stand out for me, but I'm sure to be missing some.
  Jini (224.0.1.[84|85]) seems relatively popular, but I don't really
  know anything about this technology.

John