Re: [DNSOP] Status of "let localhost be localhost"?

"Paul Hoffman" <paul.hoffman@vpnc.org> Sun, 13 August 2017 20:51 UTC

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From: "Paul Hoffman" <paul.hoffman@vpnc.org>
To: dnsop <dnsop@ietf.org>
Date: Sun, 13 Aug 2017 13:51:24 -0700
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Subject: Re: [DNSOP] Status of "let localhost be localhost"?
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On 13 Aug 2017, at 10:19, Tony Finch wrote:

>> On 12 Aug 2017, at 22:35, Ted Lemon <mellon@fugue.com> wrote:
>>
>> That is, the title of the document should be "DNS servers should 
>> return NXDOMAIN for localhost" and the abstract should say why, and 
>> then the bit about stub resolvers translating "localhost" to a 
>> reachable identifier for the localhost such as 127.1 or ::1 should be 
>> the thing that's mentioned as an aside.
>
> RFC 6761 requires recursive servers to return positive 127.0.0.1 and 
> ::1 responses, not NXDOMAIN. I can't see an explanation in the draft 
> for the change to NXDOMAIN.

And there should be. Proposed addition to the last paragraph of Section 
1:

A consequence of the requirement that the resolver APIs MUST resolve 
"localhost." and any names falling within ".localhost." to loopback 
addresses is that caching DNS servers and authoritative DNS servers MUST 
NOT resolve those names at all, and always return NXDOMAIN.

--Paul Hoffman