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

Jeroen Massar jeroen@unfix.org
Mon, 22 Apr 2002 16:18:19 +0200


Pim van Pelt [mailto:pim@ipng.nl] wrote:

> 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.
ssh -4 purgatory.unfix.org or the 'ssh purgatory.ipv4.unfix.org' trick
but I don't have that one in the outside dns apparently ;)

> 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.
IMHO you should upgrade that IPv6 connect.
Fortunatly 10mbit is still 2mbit more than my inet-uplink is capable of
And:
--- purgatory.unfix.org ping statistics ---
5 packets transmitted, 5 received, 0% loss, time 4035ms
rtt min/avg/max/mdev = 19.342/21.498/24.997/2.005 ms

vs:
--- purgatory.unfix.org ping6 statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max = 19.9/21.9/27.3 ms

Doesn't differ much for me, latency wise.
Besides that I don't have that heavy pr0n traffic desirement ;)
Btw.. did you see that nice 10/100/1000mbit port on those cute Powerbook
G4's ?
And they can do IPv6, now I'll only have to find some financial aid and
that gbit uplink <grin>

> 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'.
Absolutely, but I personally know who to kick when you bring down my
IPv6 uplink <evil grin>
Also IPng.nl fortunatly has only been down due to scheduled
maintainances and not because
it 'failed' suddenly. And you probably also remember how the couple of
times we saved
a box because the IPv4 routing was peeped and we still could reach it
over IPv6; Long live native IPv6.

This whole story ofcourse all depends on the fact how far one is in the
transition process and if you
take IPv6 for granted as a 'must-work' service level just like IPv4.
Personal taste also comes in mind ofcourse ;)

Greets,
 Jeroen