Re: [mif] [dnsext] 2nd Last Call for MIF DNS server selection document

Brian E Carpenter <brian.e.carpenter@gmail.com> Fri, 21 October 2011 19:29 UTC

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Date: Sat, 22 Oct 2011 08:29:33 +1300
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Organization: University of Auckland
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To: teemu.savolainen@nokia.com
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Cc: mif@ietf.org, dnsop@ietf.org, dnsext@ietf.org, pk@isoc.de, john_brzozowski@cable.comcast.com, dhcwg@ietf.org, denghui02@hotmail.com
Subject: Re: [mif] [dnsext] 2nd Last Call for MIF DNS server selection document
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Teemu,

I think that the spirit of what you propose is correct, but as Keith points
out it really isn't appropriate to use RFC 2119 language about a pragmatic
approach that clearly lies outside the definition of the DNS namespace.
If an implementor is willing to take the risk of transforming www.example
into www.example.com, because at the time of writing there is no TLD "example",
that's the implementor's risk, but it shouldn't be dignified with normative
keywords IMHO.

Regards
   Brian Carpenter

On 2011-10-21 20:15, teemu.savolainen@nokia.com wrote:
> Brian,
> 
> Would the following text be then ok? Please note I changed the domain addition from SHOULD to MAY, if there is going to be attempt to deprecate/redefine/update search list logics. Or do you think it should remain SHOULD?
> --
> 4.6.  Interactions with DNS search lists
> 
>    A node may be configured with DNS search list via DHCPv6
>    OPTION_DOMAIN_LIST [RFC3646] or via DHCPv4 Domain Search Option
>    [RFC3397].
> 
>    A bare name (a name without any dots) MUST be first treated as a pre-
>    DNS hostname or handled by other means that, as of this writing, are
>    under discussion in the IETF and that are out of the scope of this
>    document.  If the bare name resolution fails, the name MAY then be
>    appended with the domain information.  If the bare name is appended
>    with the domain information the described DNS server selection logic
>    SHALL be utilized for the resulting name.
> 
>    Resolution for the name containing any dots SHOULD first be attempted
>    with DNS servers of all interfaces.  Only if the resolution fails the
>    node MAY append the name with search list domain(s) and then again
>    utilize improved DNS server selection algorithm to decide which DNS
>    server(s) to contact.
> --
> 
> Best regards,
> 
> 	Teemu
> 
>> -----Original Message-----
>> From: ext Brian E Carpenter [mailto:brian.e.carpenter@gmail.com]
>> Sent: 21. lokakuuta 2011 00:50
>> To: Savolainen Teemu (Nokia-CTO/Tampere)
>> Cc: Ray.Bellis@nominet.org.uk; mif@ietf.org; dnsop@ietf.org;
>> dnsext@ietf.org; pk@isoc.de; john_brzozowski@cable.comcast.com;
>> dhcwg@ietf.org; denghui02@hotmail.com
>> Subject: Re: [mif] [dnsext] 2nd Last Call for MIF DNS server selection
>> document
>>
>> Teemu,
>>
>> I don't believe this is a topic where consensus in MIF is very relevant.
>> It needs to be decided in a much wider community rather than as a subsidiary
>> question in a MIF document. I suggest leaving it FFS (for further study) in MIF.
>>
>> Regards
>>    Brian Carpenter
>>
>> On 2011-10-20 20:01, teemu.savolainen@nokia.com wrote:
>>> Hi Ray,
>>>
>>>> -----Original Message-----
>>>> From: ext Ray Bellis [mailto:Ray.Bellis@nominet.org.uk]
>>>> Sent: 19. lokakuuta 2011 13:40
>>>> To: Savolainen Teemu (Nokia-CTO/Tampere)
>>>> Cc: <denghui02@hotmail.com>om>; <mif@ietf.org>rg>; <dnsext@ietf.org>rg>;
>>>> <dnsop@ietf.org>rg>; <dhcwg@ietf.org>rg>; <pk@isoc.de>de>;
>>>> <john_brzozowski@cable.comcast.com>
>>>> Subject: Re: [dnsext] [mif] 2nd Last Call for MIF DNS server
>>>> selection document
>>>>
>>>> I have concerns about §4.6:
>>>>
>>>> "A bare name (a name without any dots) MUST be first treated as a
>>>> pre-
>>> DNS
>>>> hostname, and only after that the name SHALL be appended with  domain
>>>> information and described DNS server selection logic be  utilized."
>>>>
>>>> When new gTLDs are introduced it is likely for brand-name gTLDs that
>>>> they will wish to use bare names in the DNS (i.e. a single label
>>>> hostname) for
>>> their
>>>> primary web sites.
>>>>
>>>> Hence bare names may become much more frequently used as DNS
>> names,
>>>> and §4.6 wouldn't permit those to work unless '.' is also in the
>>>> suffix
>>> list.
>>>> I'd like to hear the authors' thoughts on these.  I'm not sure that
>>>> this
>>> draft
>>>> necessarily needs any significant changes - it may only require
>>>> changes to ensure that bare names are also considered as potential
>>>> DNS names in their own right.
>>> Okay, I understand there is no clear consensus yet how these single
>>> label names should be handled by the resolvers at the first place?
>>> Should resolver first treat them as pre-DNS hostnames, then as DNS
>>> hostnames, and then try search list? The DNS server selection logic
>>> would be applied already when resolving single label name, i.e. the
>>> network could provide a single label domain "brand" in the domains list.
>>>
>>> Maybe section 4.6 could be like this, perhaps (changes in second
>>> paragraph and title)?
>>> --
>>> 4.6.  Interactions with DNS search lists and single label hostnames
>>>
>>>    A node may be configured with DNS search list by DHCPv6
>>>    OPTION_DOMAIN_LIST [RFC3646] or DHCPv4 Domain Search Option
>>>    [RFC3397].
>>>
>>>    A bare name (a name without any dots) MUST be first treated as a pre-
>>>    DNS hostname, after which resolution of the name SHALL be attempted
>>>    with DNS, and as a last resort the name SHALL be appended with
>>>    domain information. DNS server selection logic SHALL be
>>>    utilized for both of the latter two DNS using methods.
>>>
>>>    Resolution for the name containing any dots SHOULD first be attempted
>>>    with DNS servers of all interfaces.  Only if the resolution fails the
>>>    node SHOULD append the name with search list domain(s) and then again
>>>    utilize improved DNS server selection algorithm to decide which DNS
>>>    server(s) to contact.
>>> --
>>>
>>> Best regards,
>>>
>>> 	Teemu
>>>
>>>
>>>
>>> ----------------------------------------------------------------------
>>> --
>>>
>>> _______________________________________________
>>> mif mailing list
>>> mif@ietf.org
>>> https://www.ietf.org/mailman/listinfo/mif
>