Subject: RE: what is a site?

From: Tomohide Nagashima <[email-masked]>
Date: Tue, 03 Apr 2001 22:09:34 +0900

Form David Borman;
>>  "N" is a integer set  N = { n | n is integer , 0=< n =< 2^16 }.
>                                                           ~~~~
>Why an upper limit?
>                     ... N = {n | n is integer, 0=<n }

Upeer limit is needed, because IPv6 address is finite,
and ID for each link in the site is also finite.

Why I select 2^16 for this limitation is with considering
of subnet ID and SITE ID.

I think subnet ID in site-local and SITE ID in global is identical
, which is ID of link in one site.

This number, 16 is for currently definition, I think this could be 
changed.

>As long as Site-Local addresses are routable over Link 1, 2 and 3, this
>would be OK for me...

I think so too.
We need to add this for site definition...

>I don't see why we should use 'sub-sites'. From my point, this would be
>quite a stupid move to use sub-sites, it can cause networks to get quite
>messy. So actually, for me, the definition site, would be enough...

What I think important is not sub-sites, but the concept of "Full-Site".
Please forget "sub-site". 

With current definition of site, site can inculde site. this is logical 
matter. Asuume there is one site that has 100 links. If we pick 10 links 
which are routable each. All node in this network is off-cause routable 
with site-local address so that network is still site. If we would 
define Site with only topological matter , site can include site. 
(but off cause, we would not like to add any other definition for Site.)

So, We need to separate two site with another word.
Full-Site is what we can do that.

Full-Site is vertual concept that has 2^16 links in itself.
ISP will allocate prefix not to Site but to Full-Site.
(Because Site is too ambiguous thing to allocate prefix)

----
Tomohide Nagashima
[email-masked]

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From: Margaret Wasserman <[email-masked]>
Date: Tue, 03 Apr 2001 09:21:22 -0400

I think that this conversation is getting rather far afield...

>(but off cause, we would not like to add any other definition for Site.)

All theoretical definitions aside, it is up to the customer, in
cooperation with the ISP to define what a "site" will be.  There
will be only one "level" of site (no sub-site or full-site) 
because the IPv6 routing architecture does not allow for nested 
sites.  This is covered by the restriction that sites cannot 
overlap (sub-sites would completely overlap full-sites).

Given the current definitions in the addressing architecture, we
can define a "site" to be a group of nodes whose global addresses
contain the same 48-bit prefix, but this is meaningless.  Nodes
are not allowed to know about the boundaries in the IPv6 addressing
architecture, and they may change or be eliminated in the future.

More importantly, the practical definition of a site is:

"A group of links between which routers are configured to forward 
packets addressed to or from site-local addresses."

The routers will be explicitly configured by their administrators 
to forward (or not forward) site-local information between any
two connected links.  In most implementations, this will probably
be accomplished by setting site identifiers to the same value for 
links in the same site. Whenever any router is configured to forward 
site-local packets between two links, those links are in the same 
site.  Period.

It is up to administrators to configure their routers with 
consistent prefix information, site identifiers, etc. to produce
well-formed sites that are "convex" and do not overlap. 

Margaret

Margaret Wasserman
Director, Device Management
Wind River Networks
10 Tara Blvd, Suite 330
Nashua, NH  03062
(603) 897-2067
FAX: (603) 897-2050
[email-masked]

---

From: "Paul Francis" <[email-masked]>
Date: Tue, 3 Apr 2001 15:47:01 -0700

> packets addressed to or from site-local addresses."

One of the things that confused me about the definition of site is that the
first thing I read about it was in the context of the SLA "field" of the
IPv6 globally aggregatable address.  So I thought that "site" meant "A group
of continuous (convex, whatever) links whose address prefixes are identical
up to and including the SLA field".

This is a different definition from that based on site-local addresses, and
I find that confusing.

PF

---

From: "Tony Hain" <[email-masked]>
Date: Tue, 3 Apr 2001 15:29:45 -0700

I would normally let this go, but there has been enough confusion on this
subject that it needs to be very clear. Both Margaret and KRE are correct, a
site is defined by the boundary of a contiguous routing domain configured by
the network administrator (I assume the ISP in Margaret's definition is
providing a managed private network or just defensively filtering non-global
addresses). It is nothing more, and has no other constraints.

If someone were creating documentation and wanted to show a 'typical
example' of a site, using a building or campus would be a reasonable way to
describe the concept.  But there should not be any language in the standards
restricting it more than Margaret has here.

Tony

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Margaret Wasserman
Sent: Tuesday, April 03, 2001 6:21 AM
To: Tomohide Nagashima
Cc: [email-masked]; [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked]
Subject: RE: what is a site?

Margaret

Margaret Wasserman

---

From: Robert Elz <[email-masked]>
Date: Wed, 04 Apr 2001 11:21:39 +1000

Date:        Tue, 3 Apr 2001 15:47:01 -0700
    From:        "Paul Francis" <[email-masked]>
    Message-ID:  <001101c0bc8f$ff956560$2000a8c0@dellchan>

  | One of the things that confused me about the definition of site is that the
  | first thing I read about it was in the context of the SLA "field" of the
  | IPv6 globally aggregatable address.
  | 
  | This is a different definition from that based on site-local addresses, and
  | I find that confusing.

Yes, it is a pity that the same word is used in those two ways - they're
different without doubt, but often similar enough to seem as if they
ought represent the same thing.

kre

---

From: "Joris Dobbelsteen" <[email-masked]>
Date: Wed, 4 Apr 2001 14:54:31 +0200

Site-local are simply comparable with the private IP-addresses of IPv4
(10.x.x.x,...), where the Network Administrator bans all internal transports
from going out. Only here the config is implemented into the router...

There are no big changes that impact higher-level software (e.g.
authentication servers), so selection of these servers can be done using
IPv6, but still we need something else (e.g. DNS as MS-Win2k-Domain
uses)....
It simply has nothing to do with this and won't interfere with it in any
way...

- Joris

>[mailto:[email-masked]]On Behalf Of Tony Hain
>Sent: Wednesday, 04 April 2001 0:30
>To: Margaret Wasserman; Tomohide Nagashima