[dns-wg] Global Vs local node data in www.root-servers.org

manning bill bmanning at isi.edu
Mon Mar 17 14:27:29 UTC 2014


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 at hopcount.ca> wrote:

> 
> On 17 Mar 2014, at 7:39, John Bond <john.bond at 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




More information about the NANOG mailing list