Subject: Re: (ngtrans) The reverse lookup issue

From: Paul Vixie <[email-masked]>
Date: Wed, 03 Jul 2002 13:28:34 -0700

> Sure, you can't "trust" this name.  Just like you can't really trust
> the one in DNS PTR records, either.

using dns you get higher "trust splay" -- the party you're distrusting
about the reverse mapping is different from (and is probably differently
trustable) than the party you're distrusting about the forward mapping.

that's a good thing.

---

From: "Christian Huitema" <[email-masked]>
Date: Mon, 8 Jul 2002 11:02:19 -0700

> Yes, but in the DNS world that means that someone has delegated
> 7.6.5.4.3.2.1.0.1.0.0.2.ip6.arpa to the same group to whom .com
> zone operator has delegated example.com.  How about that.  Two
> distinct administrative regimes.  And I can generally map example.com
> more accurately than I can map 2001:0123:4567::, because the DNS
> contact database generally has the same information used for DNS
> billing; whois does not.  I also can't send email to 
> abuse@2001:0123:4567::, I can send email to [email-masked].

Well, the owner of 7.6.5.4.3.2.1.0.1.0.0.2.ip6.arpa presumably also has
delegation of some direct DNS name space, maybe "example.net" instead of
"example.com". So, two situations can occur. The delegation of the DNS
address tree matches the actual routing delegation, in our case to
"example.com", and things are fine. Or, second case, the ISP could not
for some reason delegate the DNS address tree to the user of the prefix.
In that case, the ISP can still use the trick I was describing; the
addresses will resolve to "ip6.example.net" instead of
"ip6.example.com"; or perhaps "ip6-customer-xyz.example.net" if the ISP
is inventive. We will still get some reverse mapping, and it will still
be semi-informative.

-- Christian Huitema

---

From: David Conrad <[email-masked]>
Date: Mon, 08 Jul 2002 15:49:35 -0700

On 7/8/02 1:33 PM, "Dean Anderson" <[email-masked]> wrote:
> Whois can be scaled with replication, and you can obtain local copies if
> you really do a lot of analysis.

Can you say HOSTS.TXT?  I knew you could.

Rgds,
-drc