Re: [dns-wg] Re: Re: IPv6 glue AAAA RRs in the root zone

[Brad Knowles <]

At 10:11 AM +0100 2004-07-21, Jim Reid wrote:

>  Personally, I don't see why you care about the RTT to a root server. A
>  well-behaved name server will make 4-5 queries to a root server once a
>  week or so. Why optimise that? Please note I'm not suggesting that
>  it's OK for root servers to have lousy RTTs. My name server is in
>  regular, frequent contact with other name servers that have RTTs
>  longer than 200ms.
	Well, I'm not an IPv6 expert by any stretch of the imagination, 
but the impression I got was that if you were IPv6-only, and all the 
root nameservers you can reach via IPv6 are routed via highly 
undesirable paths, then you would be in a pretty bad situation.  It's 
fine for some of those IPv6 addresses to be non-production or very 
sub-optimally routed, but I think the problem comes from when that 
happens to all of them.

	At least, that was my take.

>  Well, what other choice is there? :-) And anyway, since the overwhelming
>  bulk of the world's name servers are IPv4-only, resolution over IPv6
>  doesn't seem to be a particularly productive exercise.
	True enough.


	Thinking about it some more, I can't imagine anyone in the real 
world today who might be forced to be in an IPv6-only environment. 
However, I can imagine a lot of groups that would want significant 
testing to be done in IPv6-only environments, to try and simulate as 
best as possible what the real world would look like in the near 
future, when some people might start to be put in this boat.

	They would be unable to expand those tests to other groups, until 
the IPv6-only access is improved.  This would also force them to roll 
back the initial implementation period for real users.  And they'd be 
in a world of pain if they had already committed to IPv6-only service 
for certain groups, and then be unable to deliver to them.

	It seems to me that the folks in Asia would be most likely to be 
hurt by this, as well as anyone who is working on the "ubiquitous 
computing" environments where anything with a battery, power cord, or 
display would be given it's own IP address.

>  Why does it matter where a root name server is physically located?
>  Sorry, I should rephrase that: why does it matter where a route for a
>  root name server gets announced?
>
>  IMO a 200ms RTT over IPv6 has to be better than an infinite RTT.
	But if they're all 200ms for IPv6-only, that may effectively 
prohibit the deployment of IPv6-only networks (or even IPv6-first 
networks), until such time as the RTT is improved to a more adequate 
level.

--
Brad Knowles, <brad.knowles@localhost

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

    -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
    Assembly to the Governor, November 11, 1755

  SAGE member since 1995.  See <http://www.sage.org/> for more info.