Subject: Re: [lisp] architecturally separate name-spaces - but assumption about a single value means same thing if in both?

From: [email-masked] (Noel Chiappa)
Date: Thu, 23 Jun 2011 17:46:59 -0400 (EDT)

> From: Alia Atlas <[email-masked]>

    > I want to see something that has the assumptions written down and
    > can be implemented.

How about 'Anything that can be fed _into_ the mapping system, and get an
answer, is an LEID; anything that can be seen in the _output_ from the
mapping system is an RLOC.' Although even that's probably too precise - it
my mind were fully awake, I could probably come up with some countexamples.

    > At least one case of parts that don't work when the same bit-pattern
    > is used as an EID for one host and as an RLOC (or globally routeable
    > address) for another is:
    >  ANYWHERE that a lookup in the mapping database is done to determine
    >  if an address is an EID or RLOC

Mu. The assumption in that question (that something is _either_ an RLOC
_or_ an LEID) does not hold 100.00000% - although I wish it did! (Leaving
aside the cases of legacy addresses, which are all both at once, of
course.) If you can look up a bit-pattern in the mapping database, and get
back an answer, that bit-pattern has LEID-nature. But that doesn't mean it
can't also have RLOC-nature.

Yes, having that kind of mixed-up semantics a lot is not good; and for the
simple (and hopefully by far and away the most common) model, it does not
happen. But the Internet is large, and there are more kludges in it than any
of us dream of in our architectures....

	Noel

---

From: Alia Atlas <[email-masked]>
Date: Thu, 23 Jun 2011 18:40:17 -0400

Hi Noel,

On Thu, Jun 23, 2011 at 5:46 PM, Noel Chiappa <[email-masked]> wrote:
>    > From: Alia Atlas <[email-masked]>
>
>    > I want to see something that has the assumptions written down and
>    > can be implemented.
>
>    > At least one case of parts that don't work when the same bit-pattern
>    > is used as an EID for one host and as an RLOC (or globally routeable
>    > address) for another is:
>    >  ANYWHERE that a lookup in the mapping database is done to determine
>    >  if an address is an EID or RLOC
>

Yes - but the question is whether the same bitpattern must belong to the
same site and end-host.   Please see Joel's rephrasing of my concern.

I'm fine with the mixed up semantics for interworking and so on.  I'm not happy
about separate namespaces not being separate (e.g. independently allocatable)
without that being clearly written down.  What is written down is that they are
separate name-spaces.

> of us dream of in our architectures....

Kludges happen - I want documentation of them though.

Alia