Subject: Re: The bigoted ad hominem attacks are really annoying!

From: John C Klensin <[email-masked]>
Date: Sat, 10 Oct 1998 21:10:03 -0400 (Eastern Daylight Time)

I'm probably going to regret this, but...

On Sat, 10 Oct 1998 15:14:07 -0400 (EDT) Bob Allisat 
<[email-masked]> wrote:

>  I have attacked no-one and amply
>  apologized for any past errors
>  on my part. Jon Postel redirected
>  network traffic from it's established
>  patterns 
>...

Bob, 

Especially if you are going to continue to post this sort of 
material to technical/engineering lists, try to get your facts 
straight and to understand the relevant technology (those are 
expectations most of us have of participants in the IETF).  
Jon Postel's experiment, however well-advised or not, didn't 
divert any traffic and no end-user or intermediate site saw data 
that was any different from what they would have seen had the 
switch not been made.  Indeed, the change was substantially 
undetectable except administratively and most of us who found 
out about it (before reading about it in the papers) did so from 
telephone or email messages from third parties expressing either 
delight or chagrin; we didn't detect network disruptions or the 
server changes themselves.

In layman's terms, the "normal" situation is that all of the 
root servers except one obtain update information directly from 
that one.  This is also the normal situation with almost all of 
the zones in the DNS: there is an origin server for the zone, 
and a number of secondaries that draw information off of it.  
But it is also feasible for one secondary to "pull" information 
from another.  That isn't done terribly often, but it is done 
on an everyday basis in a number of special circumstances, e.g., 
as a step in transparent transition of primaries (origin 
servers) or when two secondaries have good connectivity with 
each other but poor or per-bit-expensive connectivity with the 
primary.

In other words, if we have an origin server, A, and two 
secondaries, B and C, it really makes no difference (modulo some 
possible issues of latency) in the data given out to users of 
those servers whether C gets its data by copying them directly 
from A or whether it copies them from B which earlier copied 
them from A.

And _that_ was the relationship that the exercise to which you 
refer tested: whether the root servers could operate in that 
sort of "some copy from the origin, others copy from one of 
them" style, rather than in "everyone copies from the origin".  
Was it desirable or necessary to try it?  Different people have 
different opinions.  Whatever political implications one might 
try to read into it aside, one group might claim that it was 
obvious that it would work for the root given that it has been 
working for years in various subsidiary zones. Another group 
might claim that we have a long and painful history in software 
and database engineering of systems that work perfectly well as 
long as boundary conditions are avoided but which fail seriously 
when they hit those boundary conditions.  Since the root of a 
tree is often different from its branches in subtle ways, that 
group would argue that this needed to be tested.

>  list. Postel's actions were similar 
>  to Kashpureff's political protest re-
>  direction of Internic's traffic only

No.  Again, leaving whatever politics and conspiracy theories 
one might come up with aside, Postel's effort delivered data 
that were identical in every way to the data that would have 
been delivered had the change not been made.  Kashpureff's 
effort apparently (I have no first-hand information) delivered 
*different* data and resulted in some end-systems accessing 
different sites than those the users had a reasonable 
expectation of reaching.

>  The network was disrupted for no reason.

Except that, unless you count the rise in telephone and email 
traffic _discussing_ the incident, there was _no_ network 
disruption.  No data were different from what they would have 
been, no user saw a site different from what would normally have 
been expected, etc.  DNS queries were resolved, and, if there 
were marginal delays, they were too small for our network 
performance monitoring arrangements to detect. It is hard for me 
to find "network disruption" in that situation, even if it makes 
good rhetoric.

    john

---

From: Randy Bush <[email-masked]>
Date: Sat, 10 Oct 1998 18:57:32 -0700 (PDT)

> each other but poor or per-bit-expensive connectivity with the 

or to get dns data through firewalls.  i suspect this is the
major use.

randy

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From: Randy Bush <[email-masked]>
Date: Sat, 10 Oct 1998 18:57:32 -0700 (PDT)

randy

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From: Brian E Carpenter <[email-masked]>
Date: Mon, 12 Oct 1998 10:42:37 +0100

John,

Surely by now you know that some people are not interested in facts,
especially when they inconveniently contradict prejudice and belief?
But thank you for trying.

   Brian

John C Klensin wrote:
> On Sat, 10 Oct 1998 15:14:07 -0400 (EDT) [somebody] wrote:
> 
> [somebody],
...

---

From: Brian E Carpenter <[email-masked]>
Date: Mon, 12 Oct 1998 10:42:37 +0100

John,

   Brian

...