A DNS question re 6to6/IPv6 host IN A records.

[Pim van Pelt]

Hi,

I agree with Pekka mostly. Having the same IN A/AAAA RRs for the
hostnames in your zonefile can make for awkward situations. 
One example might be the NL-BIT6 deployment. We have a C3640 with a 
10 mbps port acting as vlan router for IPv6. It then pushes the traffic
to the AMS-IX. If I am sitting at any IPv6 peer-site, and
ssh/ftp/telnet to my machine at the colo, and it were to have both
protocols reachable via the same name, then I would connect using IPv6
because this is preferred.

However, I like my pron to transfer fast, so the gigabit IPv4 connection
(yes I have a 1000SX board in my colo-box :) is preferrable over the
turtle-speed IPv6 connection.

The other point one might make is that IPv6 is often less well
maintained than the IPv4 network. Some tunnel might go down, zebra might
crash (or even IOS) and the connection will be left unattended by many
administrators. This is why I normally make some distinction either by
hostname 'hog.colo.bit.nl IN A' vs 'hog.colo.ipv6.bit.nl IN AAAA' or by
domain name 'hog.colo.bit.nl IN A' vs 'hog.ipng.nl IN AAAA'.

groet,
Pim

On Fri, Apr 19, 2002 at 05:02:34PM +0200, Jeroen Massar wrote:
| itojun@iijlab.net wrote:
| 
| > >In the forward/reverse zones on a 6to4 setup, should I have
| > >nanguo          IN A                203.1.96.5
| > >nanguo-v6      IN AAAA         2002:cb01:6005:2::1
| > >or
| > >nanguo          IN A                203.1.96.5
| > >nanguo          IN AAAA         2002:cb01:6005:2::1
| > >When referring to the particular host ?
| > >Either works - but which is ... errr... correct?
| > 
| > 	i recommend the latter, definitely.  with the latter 
| > you will be able o transition to IPv6 much smoother.
| 
| Definitely the latter one even with reverses.
| I do usually add something like:
| 
| purgatory	A 195.64.92.136
| purgatory	AAAA 3ffe:8114:2000:240:290:27ff:fe24:c19f
| purgatory.ipv4	A 195.64.92.136
| purgatory.ipv6	AAAA 3ffe:8114:2000:240:290:27ff:fe24:c19f
| 
| Reason: some programs can't be told to only use IPv6 or only IPv4
| (usually -6 or -4 option).
| This way one can 'force' it to use either transport.
| I do usually leave out the ipv4 though as I don't use that much any more
| anyways ;)
| 
| Greets,
|  Jeroen

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Pim van Pelt                 Email: pim@ipng.nl
http://www.ipng.nl/             IPv6 Deployment
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