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 <jab...@hopcount.ca> wrote: > > On 17 Mar 2014, at 7:39, John Bond <john.b...@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
