Re: [dhcwg] RE: IPv6 Host Configuration of Recursive DNS Server

Ted Lemon <> Mon, 07 June 2004 19:36 UTC

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From: Ted Lemon <>
Subject: Re: [dhcwg] RE: IPv6 Host Configuration of Recursive DNS Server
Date: Mon, 07 Jun 2004 12:24:26 -0700
To: Christian Huitema <>
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Cc: IPv6 DNS Configuration <>, IPv6 WG <>,, V6OPS WG <>, DHC WG <>, Jaehoon Paul Jeong <>
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On Jun 6, 2004, at 9:28 PM, Christian Huitema wrote:
> 1) In the disadvantage of DHCPv6 section, you ought to mention that
> there is a ensure that the DHCP server always returns an up-to-date
> value for the address of the preferred recursive DNS server. In large
> networks, this is not trivial: the notion of which server is closest
> depends on routing configuration and on server status, all of which are
> dynamic. In contrast, the anycast approach guarantees that the request
> will reach the closest server.

This is really more of an advantage of using an anycast address over 
using a unicast address, and has nothing to do with DHCPv6.   If you 
want this functionality, you can use DHCPv6 to configure the anycast 
address, or you can hard-code the anycast address.   The question we're 
trying to address is really how we configure nodes as they come on to 
the network, not with what we configure them.   The reason that anycast 
has a place in this discussion is that it's the only possible value 
that you could just hard-code into the client and thereby bypass 
configuration altogether.

We need to be very careful in discussing this draft not to get confused 
about what the draft does.   It does not say "this is the solution."   
Rather, it is essentially a sales tool which tries to present the 
advantages and disadvantages of each option, so that the buyer (the 
IESG, I guess) can make an informed choice between them.   So please 
let us not digress into deep, detailed discussions about why the other 
guy's choice is wrong - just say what's good about the proposal you 
favor, and if you want to be honest, discuss any disadvantages of which 
you're aware.

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