www6 ?

Petra Zeidler zeidlerp at cw.net
Tue Apr 24 15:09:13 CEST 2007

Thus wrote Doug Barton (dougb at dougbarton.us):

> I've read this thread with interest, but I am still curious, what
> problem are you trying to solve here? Is this something you want for
> diagnostic purposes, for end user purposes, other?

A mixture, really. Take f.e. ftp.netbsd.org:
ftp.netbsd.org has address
ftp.netbsd.org has IPv6 address 2001:4f8:1:c:230:48ff:fe31:43f2

there also is:
ftp4.netbsd.org has address
(and no AAAA)
ftp6.netbsd.org has IPv6 address 2001:4f8:1:c:230:48ff:fe31:43f2
(and no A)

there's sufficient people that have some IPv6 connectivity, but it sucks
badly, so they want to make sure they connect via v4 (because their hosts
tend to prefer v6 if it's working at all), so they use the ftp4 variant.

In other cases, they have a special deal for IPv6 traffic, so they only want
to connect via v6 (or fail if it's not working), and use ftp6.

The majority doesn't care and uses ftp.

Also, in some cases people are reporting strange connection problems
and then get asked to use the 4 and 6 variants separately to find out
if their problem is protocol dependent.

Is that sufficient explanation-by-example of why one would want to have
distinct names for the A and AAAA addresses of a dual-stacked host,
in addition to its general one?

	Petra Zeidler
i.A. Petra Zeidler, OSS     Phone: +49 89 92699 0       FAX: +49 89 92699 802
Cable & Wireless Telecommunication Services GmbH
Landsberger Str 155, D-80687 Muenchen, Deutschland
Geschaeftsfuehrer Francois Goreux, Richard Pennal
Amtsgericht Muenchen HRB 146 617

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