Hi Bob, > -----Original Message----- > From: Bob Hinden [mailto:bob.hin...@gmail.com] > Sent: Tuesday, November 24, 2009 2:52 PM > To: Thomas Narten > Cc: Bob Hinden; Templin, Fred L; ipv6@ietf.org > Subject: Re: New draft on "Stub Router Advertisements in IPv6 Neighbor > Discovery" > > > On Nov 24, 2009, at 11:37 AM, Thomas Narten wrote: > > > Fred, > > > > Can you summarize what problem this draft is aimed at solving? What > > is the motivation for this draft? (I've read it, but I don't > > understand what the benefit of this approach is or what problem it > > solves.) > > > > In the Introduction says: > > A stub router is any router that attaches stub networks to the link, > but does not itself attach the link to a provider network. Here, a > "stub network" could be as simple as a small collection of IPv6 > links, or as large as a complex corporate enterprise network. Stub > routers are said to be "non-authoritative" for the link, since they > cannot themselves provide forwarding services for packets emanating > from their stub networks without using another router on the link as > a transit. > > I disagree with this and don't think that a router that is connected to an > ISP is inherrently higher > priority than other routers.
I don't understand this comment. The entity I am calling "stub router" is simply trying to find a way to forward packets on to their final destination using the best possible exit router. There is nothing said or implied about "priority". > This is definitely not true in enterprise networks. This is actually all about enterprise networks; in some ways, an ISP network can be seen as just a special case of an Enterprise network. > We have other ways of doing this in a more general fashion such as RFC4191 > "Default Router > Preferences and More-Specific Routes". Exactly; this document very much expects that stub routers will advertise RFC4191 more-specific routers. > I don't see any need to define "stub routers" and see a lot > of harm doing so. For example, in an enterprise, routing may be setup to > keep the traffic inside of > the enterprise for a long as possible and not use the local ISP connection. > The inter-enterprise > links might be much faster. The way it works is that the stub router may have a default route but may not have a more-specific route to the destination inside the enterprise. It then sends the packet to a default router which hairpins it back to a router within the enterprise that aggregates the more-specific route, but also sends a redirect back to the stub router that originated the packet. The stub router then sends an RA to the enterprise router that aggregates the more-specific route, then subsequent packets flow through the more-specific route and eliminate the dogleg. So yes; packets stay inside the enterprise and do not go out the local ISP connection only to come back in again. Fred fred.l.temp...@boeing.com > Bob -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
