Re: IPv6 addresses within URLs

John C Klensin (klensin@mci.net)
Mon, 17 Nov 1997 09:04:52 -0500 (EST)


Date: Mon, 17 Nov 1997 09:04:52 -0500 (EST)
From: John C Klensin <klensin@mci.net>
Subject: Re: IPv6 addresses within URLs
In-reply-to: <346A11C1.20463C40@parc.xerox.com>
To: Larry Masinter <masinter@parc.xerox.com>
Cc: uri@bunyip.com
Message-id: <SIMEON.9711170952.D@tp7.Jck.com>


On Wed, 12 Nov 1997 12:29:53 -0800 (PST) Larry Masinter 
<masinter@parc.xerox.com> wrote:

> draft-ietf-ipngwg-aaaa-00.txt
> 
> proposes another method which would work for including IPv6 addresses:
> 
>    An IPv6 address is represented as a name in the IP6.INT domain by a
>    sequence of nibbles separated by dots with the suffix ".IP6.INT". The
>    sequence of nibbles is encoded in reverse order, i.e. the low-order
>...

Larry,

I was hoping that someone else would pick up on this, but...

(i) 
b.a.9.8.7.6.5.0.4.0.0.0.3.0.0.0.7.0.0.0.1.0.0.0.0.0.0.0.1.2.3.4.IP6.INT. 
is amazingly disgusting and the chance that humans could 
get it right is pretty nearly zero.  Quoting a few colons, 
if needed, seems much less painful.

(ii) One of the general assumptions about IPv6 is that 
renumbering will occur fairly frequently.   That will make 
use of explicit addresses in URLs a fairly bad idea and 
something we don't want to encourage (I suppose the above 
form would have that effect, but, still...).

(iii) I don't know what has gotten into the heads of the 
IPng WG, but the only good place for using literal 
addresses is when the DNS isn't working or isn't available. 
Doing something that requires DNS resolution creates a 
nasty recursion loop problem; designing something that 
requires special-casing within a subdomain (when the TLD 
and its other subdomain are handled normally) strikes me as 
incredibly bad design.

(iv) you might want to take a look at the address literal 
discussion in draft-ietf-drums-smtpupd-NN.  It is pretty 
terrible and would require escapes, but might a better 
approach than inventing something separate for URLs.

   john