Re: [Exim] Off topic: IPv6 [was: Very Slow response: exim …

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Author: Philip Hazel
Date:  
To: Hayling, David
CC: Exim Users, 'tjc@ecs.soton.ac.uk'
Subject: Re: [Exim] Off topic: IPv6 [was: Very Slow response: exim -bt]
On Fri, 10 Aug 2001, Hayling, David wrote:

> Having just seen the latest O'Reilly book "DNS and Bind" 4th ed Apr 2001, I
> note on page 302 it says
> "Use of the old AAAA record and ip6.int is now deprecated" So who has
> changed their mind? Did the IETF originally deprecate AAAA?


Yes. They have changed their mind. (Well, the consensus at the meeting
was that way. I guess they could change their mind again. I'm told
there is still a lot of warfare on the mailing list.)

> The O'Reilly book goes on to say on page 302 "The main reason the AAAA
> record and the ip6.int reverse-mapping scheme were replaced was because they
> made network renumbering difficult". Does the IETF have a solution to
> renumbering when the AAAA scheme is in use?


At the IETF this morning there was a presentation and discussion about
renumbering in IPv6 in general. (You could have watched on the mbone.)
As I understood it, some people think renumbering is going to happen
frequently; others don't believe that it can only be made to work
rarely. People have strong opinions about it. Some scenarios to be
pursued were laid out. It all seems very fluid.

Basically my impression of the AAAA/A6 argument was: "renumbering is
still itself undergoing huge discussion. AAAA is already deployed and
working perfectly satisfactorily in many networks[*]. A6 seems to have a
number of problems of its own (e.g. longer queries) and it is not clear
what problems it might solve. Therefore, we should go with AAAA at this
time."

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[*] Out in the Far East they are well ahead on Ipv6, it seems, owing to
a much more severe shortage of IPv4 addresses than we have in the west.

-- 
Philip Hazel            University of Cambridge Computing Service,
ph10@???      Cambridge, England. Phone: +44 1223 334714.