Re: Status of subnet-local multicast?

Stig Venaas <stig@venaas.com> Wed, 27 June 2012 17:53 UTC

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Date: Wed, 27 Jun 2012 10:53:00 -0700
From: Stig Venaas <stig@venaas.com>
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Subject: Re: Status of subnet-local multicast?
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On 6/27/2012 10:13 AM, Kerry Lynn wrote:
> Greetings,
>
> RFC 3484 section 3.1 defines "subnet-local (0x03)" multicast scope, but
> later RFC 4291 section 2.7 defines this multicast scope value as reserved.
> Can I ask if the later interpretation is the correct one?
>
> I ask in the context of e.g.
> http://tools.ietf.org/html/draft-lynn-homenet-site-mdns
> where we need a scope greater than link-local in order to span a 6LoWPAN
> subnet, but less than site-local in order to reserve the property "Each
> interface
> belongs to exactly one zone of each possible scope." for future site-local
> protocols that might include the 6LoWPAN router port.
>
> Should I select admin-local scope, or is subnet-local scope available
> for use?

I've always been a bit curious why it got marked as reserved. It was
(unassigned) in RFC 2373, but reserved in RFC 3513. I don't remember
any discussion on this.

It seems 4 admin-local would be appropriate then. Unless perhaps if 3
is somehow reserved to allow for maybe future use like this...

Stig

>
> Thanks, -K-
>
>
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