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

Brian E Carpenter <> Thu, 20 October 2011 21:50 UTC

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Date: Fri, 21 Oct 2011 10:50:09 +1300
From: Brian E Carpenter <>
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Subject: Re: [mif] [dnsext] 2nd Last Call for MIF DNS server selection document
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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.

   Brian Carpenter

On 2011-10-20 20:01, wrote:
> Hi Ray,
>> -----Original Message-----
>> From: ext Ray Bellis []
>> Sent: 19. lokakuuta 2011 13:40
>> To: Savolainen Teemu (Nokia-CTO/Tampere)
>> Cc: <>om>; <>rg>; <>rg>;
>> <>rg>; <>rg>; <>de>;
>> <>
>> 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-
>> 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
> ------------------------------------------------------------------------
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