nanog mailing list archives

Re: Deploying IPv6 in a datacenter (Was: Awful quiet?)


From: Daniel Roesen <dr () cluenet de>
Date: Wed, 21 Dec 2005 23:18:26 +0100


On Wed, Dec 21, 2005 at 07:50:14AM -0600, Kevin Day wrote:
1) IPv6 on the internet overall seems a bit unreliable at the moment.  
Entire /32's disappear and reappear, gone for days at a time.

That's certainly true for people not doing it "in production". But that
ain't a problem as they aren't doing it... in production. :-)

The most common path over IPv6 from the US to Europe is US->JP->US->EU.

Sorry, but that's not true anymore on grand scale. That might still be
valid for some exceptionally bad IPv6 providers who still "do it 6bone
style". Fortunately, those don't play any too significant role anymore in
global IPv6 routing (which was hard work to achieve).

I realize this may be specific to our connection itself, but browsing  
looking glasses seems to back up that it's not just us.

That'd suprise me. Could you give examples?

2) Lots of providers who are running IPv6 aren't taking it as  
seriously as IPv4. Manual prefix filters, NOC staff that doesn't even  
know they're running IPv6, etc.

ACK, but "manual prefix filters" is often rooted in "there are no good
tools to do the job". I've seen folks trying to beat RtConfig for months
into doing sensible things. :-)

3) Some key pieces of internet infrastructure are IPv6 oblivious.  
ARIN's route registry doesn't support the "route6" objects, for example.

Don't get me started about IRRs. :-(

5) Our DNS software(djbdns) supports IPv6, kind of. WIth patches you  
can enter AAAA records, but only by entering 32 digit hexadecimal  
numbers with no colons or abbreviations. We were never able to get it  
to respond to queries over IPv6, so of all our DNS is still IPv4.

Then stop using incomplete and cumbersome software from authors with
strong religious believes and a disconnection from any technological
advances of the last $many years. :-)

"Use the right tools for the job".

10) Smaller than normal MTUs seem much more common on IPv6, and it is  
exposing PMTUD breakage on a lot of people's networks.

It is, but we have tracked down most of them... at least the ones we
noticed. I don't experience PMTUD problems anymore since long... the
last one is prolly over half a year ago. And I use IPv6 on all my
servers, desktops and laptop. :-)

11) Almost without fail, the path an IPv6 user takes to reach us (and  
vice-versa) is less optimal than the IPv4 route. Users are being  
penalized for turning on IPv6, since they have no way to fall back to  
IPv4 on a site-by-site basis when using a web browser.

That is indeed a problem. How big the penalty is, depends heavily on
your choice of upstream provider(s). The isle of sanity gets bigger and
bigger, and networks with bad IPv6 connectivity become more seldom
(relatively).

Thank you for sharing your experience!

BTW, what timeframe are we talking about? Things have changed massively
over the last 12-18 months.


Best regards,
Daniel

-- 
CLUE-RIPE -- Jabber: dr () cluenet de -- dr@IRCnet -- PGP: 0xA85C8AA0


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