> Just re-read RFC 2501, and  I don't see mention of "multi-hop
subnets".
> Can you point out where this is described?

I don't think RFC 2501 is strong on that the networks
it describes are subnets in the Internet sense, although
that's widely assumed in the IETF MANET community, see for
example Section 7 of RFC 3561 or Section 11.1 of RFC 3626.
Multi-hop of course is covered in RFC 2501 - the first
paragraph of the Introduction introduces the point for
the first time.

That a MANET should be a subnet (common prefix) is
primarily for the benefit of the Internet to which it
is attached, the MANET itself generally derives little
benefit from this (although there's an exception in
OLSRv2 for example, it will allow more efficient messages,
but that's still only secondary). Of course this benefit
to the Internet is important, which is one reason why
Autoconf should be useful.

I would agree that spelling this out in a single document,
son-of-RFC-2501 if you like, would be beneficial. That
should be a task of the Autoconf WG and/or the Manet WG
(there's a major overlap of participants of course) rather
than a hurdle to forming an Autoconf WG and starting its
work however in my/our (for some value of "our") opinion.

>> One additional point I'd note, is that MANETs attached to the
>> Internet are almost exclusively viewed as stub networks (for
>> reasons of bandwidth and reliability at the least).

> Is it an assumption that a MANET will only function as a stub network,
or
> is it an enforceable restriction?  For example, is there a mechanism
> that can be used to prevent a MANET from becoming attached at multiple

> points, becoming a transit network?

A MANET may be attached at multiple points and still not be
a transit network; this is generally assumed. Current MANET
routing protocols are dealing with the issue inside the
MANET, and can handle the concept of multiple gateways.
Ensuring that the MANET isn't used as a transit network
is down to the gateways not putting any entries in their
routing tables for non-MANET destinations with next hop
in the MANET. This is down to the gateways knowing which
are MANET addresses (or those MANET addresses being unknown
to the non-MANET routing protocol used by the gateway
on its Internet side). This may be pre-configured in some
systems, but existing MANET autoconf work on which work
will be based assumes that if we have multiple gateways
that some sort of coordination between them is needed,
this would be easily picked up from that.


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