Monday, November 17, 2014

IPv6: The first step

I often hear comments like "Where do I start on IPv6?"; I have two answers.

Tuesday, November 11, 2014

What's Wrong with NAT

What's wrong with NAT?

NAT is often proposed as a supposedly-viable alternative to IPv6 deployment. NAT was an attempt to mitigate IPv4 address depletion, to give us time to migrate to IPv6, but not to replace IPv6. As the number of devices connected to the Internet grows, the Internet needs more addresses. IPv6 generally removes the need for any NAT at all, whereas more NAT breaks more applications. Still, what's wrong with NAT?

Wednesday, October 29, 2014

IPv4 crutches

Back in June I participated in Turn off IPv4 Day as a show of solidarity. I had grand plans to write up a long post about the issues encountered throughout the day, but I had already done similar versions of this activity in the lab, so there weren't a whole lot of surprises. There was one gotcha right at the beginning that did catch me a bit off-guard: the Internet looked a lot darker than I anticipated.

Friday, June 6, 2014


The other day on IRC, the bot for one of the channels I frequent reconnected, and I noticed it was coming in over IPv4. I knew the host it was on is IPv6 capable, so I jokingly asked it "y u no ipv6?". The bot's owner told me "patches welcome" and pointed me at the bot's source. Now, some of you recall I cringe a bit when someone says that to me, but I decided to poke around.

Wednesday, May 14, 2014

Monitor your IPv6

Many of my recent posts have been about sites that have not yet enabled IPv6. For those of you who have done so: Good on ya! Now, do you monitor it?

I've been encountering an increasing number of web sites with AAAA records, but the addresses listed therein either do not answer (timeout) or refuse the connection (RST). On dual-stack networks, these conditions are often masked by Happy Eyeballs. These situations could also result in inconsistent behavior.

Many mobile devices are being released with IPv6 only. This means in the case of a timeout, the user see an unreachable message (and in the case of a timeout, wait to see it) because there is no IPv4 network on which to fall back to try the A record. These aren't just fringe hobbyist users. This is the booming mobile market driving the continued growth of the Internet.

Make sure you not only monitor your IPv6 the same way you do IPv4, but also act on it the same way. Treat outages on either network as production. Your customers will thank you.

(Joni adds: Be sure you really are monitoring what you think you are. Some tools, when presented with a hostname having both A and AAAA records, will do standard fallback (eg: curl, dig), whereas some tools require the protocol be explicitly called out (eg: ping / ping6).)

Tuesday, March 11, 2014

A call to ISPs

The response from Time Warner Cable every time I call to ask about IPv6 involves some variant on "We are not deploying IPv6 because we have enough IPv4 addresses." This response is wrong on at least three points that I would like to address here.
  • What about the other end? It's all well and good that you have enough IPv4 address space (for now, see next point), but what about the other system I'm trying to communicate with? In other parts of the world ISPs aren't so lucky. The European and Asia-Pacific regions are already out of addresses, and ISPs in those areas are carefully conserving what little IPv4 space they have left.
  • Growing pains. While you may have "a very healthy inventory of IPv4 addresses available" (Michael Tate, TWCBC Account Consultant, East Region, 22 Apr 2013) at present, this will not continue to be the case... unless you don't plan on growing your customer base any further. Deployments of IPv6 alongside IPv4 should already be underway, if not complete, to ensure there has been adequate testing not only on the part of the ISP but at all the customer sites. Deploying IPv6 "only ... in instances where IPv4 addresses are completely out" (@TWC_Help, Twitter DM, 10 Mar 2014) puts everyone at a disadvantage.
  • The whole Internet. I touched on this in a previous post with regard to content providers, but the same call should go out to the ISPs. Why do I want to subscribe to an ISP that isn't giving me access to all of the Internet?
I've had the good fortune of bumping into Wes George on the Google+ IPv6 discussion group back in October 2013. He was very interested to hear about my experiences and has been nothing but incredibly helpful as we've exchanged emails these past few months. Despite his efforts, we clearly still have a long way to go.

I pick on TWC here because they are my ISP and I've had the most direct experience with them. My impression is that other ISPs are behaving in a similar fashion. I hope we can all get moving before this migration gets any costlier.

Thursday, February 6, 2014

Photo gallery now live

I am pleased to announce the IPv6 photo gallery is now live on our site. If you have received an IPv6 sticker at one of our presentations, or have some other interesting use of IPv6, please send us a picture! We'd love to feature it in the gallery.