Re: Bash IETF, not RIRs

[Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>]

Iljitsch;

> > Back to your idea of having a full routing table in each host. We've 
> > talked about this and things haven't changed in the mean time.

Read the draft before talking or things won't change in your mind.

  With regard to multihoming, when an end system want to communicate
  with a multihomed end system, the end system must be able to select
  most appropriate (based on the local information) destination address
  of the multihomed end system.

  However, some think it of course to separate routers and nodes and
  let hosts not have routing information (which means the current IPv6
  architecture is broken) and, worse, let most routers use default
  routes.

  With detailed route information, end systems can use the information
  as a hint to select the best destination address.  However, with
  default route, end systems have no idea on what is the best address
  and must blindly try all the possibilities at random.

> > Without 
> > aggregation, this makes sense, as a host then knows what's reachable 
> > and what isn't, and maybe even gets to determine which path to a 
> > certain destination is shorter. But all this very useful information 
> > is hidden behind aggregation. For instance, if you want to determine 
> > whether you want to reach me through my 3ffe:2500:310::/48 or my 
> > 2001:888:1dde::/48 prefix, you're not going to be able to see whether 
> > those are reachable, as the /48s aren't going to be in the global 
> > routing table, just 3ffe:2500::/32 and 2001:888::/32.

If routing system tells you that some address is not reachable,
which is impossible with a default route, the address is not
reachable.

But, don't expect routing system offer more accuracy.

Aggregation is not essential.

Even if you use host routes, exsiting of a host route does not
guarantee that the host is reachable. It may be just a result of
misconfiguration.

Routing systems give hint to help hosts make efficient decisions.

Note also that this is not the only reason to have full routing table.

The fundamental reason is because it is end to end.

							Masataka Ohta