[147976] in North American Network Operators' Group
Re: Misconceptions, was: IPv6 RA vs DHCPv6 - The chosen one?
daemon@ATHENA.MIT.EDU (Masataka Ohta)
Wed Dec 28 21:50:14 2011
Date: Thu, 29 Dec 2011 11:51:00 +0900
From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
To: nanog@nanog.org
In-Reply-To: <14160.1325099085@turing-police.cc.vt.edu>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Valdis.Kletnieks@vt.edu wrote:
>> According to the end to end argument, the only possible solution
>> to the problem, with no complete or correct alternatives, is to
>> let hosts directly participate in IGP activities.
>
> That's only for hosts that are actively trying to communicate on more than one
> interface at a time,
Note that the end to end argument has the following
statement I omitted to quote:
(Sometimes an incomplete version of the function provided
by the communication system may be useful as a performance
enhancement.)
That is, there are incomplete solutions by intermediate systems
which sometimes work.
> and even then quite often the *actual* right answer isn't
> "run an IGP", it's "insert static routes for the subnets you need to reach via
> the other interface"(*).
With manual configuration, you can do anything. But, aren't we
talking about autoconfiguration?
> If it's a laptop that has both a wireless and a wired connection
> active, usually a simple "prefer wired" or "prefer wireless" is
> sufficient.
Usually? Can you see the word "complete" in the end to end argument?
> Quick sanity check on the hypothesis: Does Windows ship with an IGP enabled by
> default?
Sanity check with Windows? Are you sure?
> If not, why does the net continue to function just fine without it?
It is often incomplete and incorrect unnecessarily requiring
manual reconfigurations.
> (*) If you think I'm going to run an IGP on some of my file servers when
> "default route to the world out the public 1G interface, and 5 static routes
> describing the private 10G network" is actually the *desired* semantic because
> if anybody re-engineers the 10G net enough to make me change the routes, I have
> *other* things to change as well, like iptables entries and /etc/exports and so
> on. I don't *want* an IGP changing that stuff around wiithout the liveware
> taking a meeting to discuss deployment of the change.
If you are saying SLAAC is not enough in your case with
complicated manual management, I don't think I have to
argue against you on how to simplify it.
Masataka Ohta
