Subject: RE: comments/questions on draft-ietf-malloc-madcap-04.txt

From: Dave Thaler <[email-masked]>
Date: Fri, 7 May 1999 16:02:51 -0700

My understanding is that for well-known scopes, such as global,
it ought to be possible for a client to skip the scope enumeration
step, and just send a request.

My question then, if you agree with the above, is:
what's the scope ID for global?  Is it the first global address (224.0.1.0)?
Or is it 0.0.0.0?

Secondly, as Steve pointed out a while ago, the scope end address
is required if the client wants to use scope-relative addresses
(which is why it's already there in MADCAP).
Since the server may be allocating out of a smaller range than
the full scope range, I believe the spec should specifically state
that the scope range given to the client is not necessarily the
scope range the server allocates from (or does it already say this
somewhere?)   A corrolary is that the Scope ID is not necessarily
the first address in the range the server is allocating from.

-Dave

---

From: Steve Hanna <[email-masked]>
Date: Mon, 10 May 1999 10:59:20 -0400

> step, and just send a request.

I agree. If a particular server does not support the indicated scope,
the server will not respond to a DISCOVER message.

> what's the scope ID for global?  Is it the first global
> address (224.0.1.0)? Or is it 0.0.0.0?

From section 3.5 of draft-ietf-malloc-madcap-04.txt:

   ... The scope id is the first multicast
   address in the scope. ...

So the scope ID for the global scope is 224.0.1.0.

> the first address in the range the server is allocating from.

Well, the MADCAP spec doesn't really get into the internal mechanics of
how the server allocates addresses. The server might have one or more
ranges of addresses over which it has complete control. Or it might
request addresses as needed from a pool. There might be an operator with
a pencil and paper, crossing things off a list. It shouldn't make any
difference to the client (although things might be a bit slow in the
pencil and paper case).

If you think it would be useful to say something about this, I'll see
what I can do.

-Steve