Re: [dhcwg] Comments on 22 rev of the draft

Vijay Bhaskar A K <> Wed, 23 January 2002 18:51 UTC

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From: Vijay Bhaskar A K <>
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Subject: Re: [dhcwg] Comments on 22 rev of the draft
Date: Thu, 24 Jan 2002 00:10:27 +0530
In-Reply-To: <> from Ted Lemon at Jan "23, " 2002 "06:12:02" pm
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> What possible use can there be in allowing the client to select the prefix 
> that it wants?   

Please go through the follow scenario.  Router is advertising  3ffe::/64
prefix and a host has generated an address of prefix  3ffe::/64  using
router  advertisements.  Now, the host  needs  some  more  addresses  of
prefix  3ffe::/64.  It chooses to use stateful  autoconf  (dhcpv6).  The
server  sends  advertise  saying  that,  it can  allocate  addresses  in
3ffe::/64  and  5ffe::/64.  Since,  the  client's  wish  is to get  only
3ffe::/64,  it can tell the server its  preference  for the prefix while
sending  Request.  This will help in server not allocating the addresses
that the client doesn't want.

Moreover, if the client wants to communicate  with the external site, it
requires  global  rather  than site local  addresses.  Here also, it can
show the preference.

DHCP clients are intended to arrange for ad-hoc 
> connections.   Under what circumstances would the client have any knowledge 
> of what prefixes might be better than others?

Obviosuly, the client using the stateless  autoconf,  knows the prefixes
in the link, (by router advertisements).  From the Advertise messages of
the various servers, it knows about the prefixes in the link.

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