Message-Id: <6.2.3.4.2.20050905110227.0446ac40@mail.jefsey.com>
Date: Mon, 05 Sep 2005 11:38:28 +0200
To: "Christian Huitema" <huitema@windows.microsoft.com>,
	"Andrew Sullivan" <andrew@ca.afilias.info>, <ietf@ietf.org>
From: "JFC (Jefsey) Morfin" <jefsey@jefsey.com>
In-Reply-To: <DAC3FCB50E31C54987CD10797DA511BA10A5A1E2@WIN-MSG-10.wingro
	up.windeploy.ntdev.microsoft.com>
References: <DAC3FCB50E31C54987CD10797DA511BA10A5A1E2@WIN-MSG-10.wingroup.windeploy.ntdev.microsoft.com>
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Subject: RE: Last Call: 'Linklocal Multicast Name Resolution (LLMNR)'
 toProposed Standard
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At 10:45 05/09/2005, Christian Huitema wrote:
> > My greatest concern is that the document as it stands is likely to
> > cause a large number of bogus DNS queries.  If the protocol is widely
> > adopted, it seems probable that many clients will have LLMNR enabled
> > on an interface in a situation where a DNS server has been configured
> > (as described in section 2).  In that case, every LLMNR query will
> > entail (possibly more than) one DNS query, because of the provision,
> > "All attempts to resolve the name via DNS on all interfaces have
> > failed after exhausting the searchlist."  Such DNS queries will become
> > commonplace if the protocol is widely adopted and widely used.  This
> > feature of the design appears to increase the burden on the entire
> > Internet infrastructure in order to support unshared infrastructure.
>
>Uh, no.

Christian,
I am not sure I understand you correctly. What Andrew fears, if I am 
correct, is an increase of the number of resolution requests. I feel 
you answer on the number of DNS querries per resolution request?

I would be interested in better understanding the details of the 
Windows mechanism: where to best find it described? It could be used 
for similar needs (registry distribution) I work on. I understand 
that what you name the "search list" is Hosts.txt? and that the idea 
is to either add a smarter database or a broadcast t querry to 
complete the local Host.txt service? However I fail to see what this 
really brings that a local dynamic name server would not provide with 
more security and services?

thank you
jfc




>LLMNR does not create additional DNS queries. Applications do not issue
>LLMNR requests, they issue name resolution requests. When a name
>resolution request is issued, the current behavior is to submit the
>request to the DNS, possibly applying a "search list". LLMNR does not
>change that. LLMNR adds an additional transaction at the end of the
>search list, falling back to local multicast resolution if the
>infrastructure could not resolve the query authoritatively.
>
>The part about multiple interfaces is also the current behavior in
>multi-homed hosts. In theory, DNS requests sent to different servers
>over different interfaces should all be equivalent. In practice, they
>are not. Some names can be resolved through some interfaces, and not
>through others. To be sure, systems end up sending the requests on
>multiple interfaces.
>
>-- Christian Huitema
>
>_______________________________________________
>Ietf mailing list
>Ietf@ietf.org
>https://www1.ietf.org/mailman/listinfo/ietf


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