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Re: [dns-wg] Global Vs local node data in www.root-servers.org
From: manning bill <bmanning () isi edu>
Date: Mon, 17 Mar 2014 07:27:29 -0700

alas, our service predates Joe’s marvelous text.

“B” provides its services locally to its upstream ISPs.
We don’t play routing tricks, impose routing policy, or attempt to 
influence prefix announcement.

/bill
Neca eos omnes.  Deus suos agnoscet.

On 17March2014Monday, at 7:17, Joe Abley <jabley () hopcount ca> wrote:


On 17 Mar 2014, at 7:39, John Bond <john.bond () icann org> wrote:

Global and Local nodes are very loosely defined terms.  However general
consensus of a local node is one that has a desired routing policy which
does not allow the service supernets to propagate globally.  As we impose
no policy we mark all nodes as global.

I think the taxonomy is probably my fault. At least, I thought I invented it when I wrote

 http://ftp.isc.org/isc/pubs/tn/isc-tn-2003-1.txt

the pertinent text of which is this:

  Two classes of node are described in this document:

  Global Nodes advertise their service supernets such that they are
     propagated globally through the routing system (i.e. they
     advertise them for transit), and hence potentially provide service
     for the entire Internet.

  Local Nodes advertise their service supernets such that the radius of
     propagation in the routing system is limited, and hence provide
     service for a contained local catchment area.

  Global Nodes provide a baseline degree of proximity to the entire
  Internet. Multiple global nodes are deployed to ensure that the
  general availability of the service does not rely on the availability
  or reachability of a single global node.

  Local Nodes provide contained regions of optimisation. Clients within
  the catchment area of a local node may have their queries serviced by
  a Local Node, rather than one of the Global Nodes.

The operational considerations that you mention would have been great for me to think about when I wrote that text 
(i.e. it's the intention of the originator of the route that's important, not the practical limit to propagation of 
the route due to the policies of other networks).

We did a slightly better job in RFC 4768 (e.g. "in such a way", "potentially"):

  Local-Scope Anycast:  reachability information for the anycast
     Service Address is propagated through a routing system in such a
     way that a particular anycast node is only visible to a subset of
     the whole routing system.

  Local Node:  an Anycast Node providing service using a Local-Scope
     Anycast Address.

  Global-Scope Anycast:  reachability information for the anycast
     Service Address is propagated through a routing system in such a
     way that a particular anycast node is potentially visible to the
     whole routing system.

  Global Node:  an Anycast Node providing service using a Global-Scope
     Anycast Address.


Joe



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