Archive for February, 2014

History

I’ve been running an IPv6 tunnel at home since 2010. Why? Several reasons. I’d like to use IPv6 enough that I feel comfortable with it. I’d also like to encourage service providers and web sites to start incorporating it, rather than playing funny games to extend IPv4. And finally, I am convinced that pretty soon, there will be desirable services on the web that are only available on IPv6… so far I have not heard of a killer app that is not accessible on IPv4, but it will come.

For all of this time, I have been running a tunnel from my home router to Hurricane Electric, a leading provider of IPv6 services. They use a system called “6in4”, which bundles up your IPv6 packets inside IP packets of type “protocol 41”. Most folks are familiar with TCP (6), UDP (17), ICMP (1), or maybe even SCTP (132). Well there are a lot of other types of IP packets, and protocol 41 is used to bundle IPv6 traffic inside of IPv4 packets.

The thing is, to get a 6in4 tunnel to work, you have to tell your router to allow IP protocol 41 packets through. Most routers do not do this by default.

Outage

This weekend, we had an internet outage at home. So I rigged up my router at home to connect to the internet through my neighbor’s wifi instead of through our DSL modem (this is pretty easy to do with an old WRT54G router, re-flashed with “dd-wrt” firmware). The problem is that I don’t really have any control over my neighbor’s router, and it does not pass these protocol 41 packets through. So my IPv6 quit working.

That, by itself, would not be so bad. The traditional IPv4 network still works OK. But since my home network DOES have IPv6, my web browser expects to be able to make IPv6 connections. So when I go to a web site like google.com, my browser first tries an IPv6 connection to Google. After several seconds, that attempt times out and then the browser tries an IPv4 connection. Multiply by every HTTP request, and it starts feeling dreadfully slow.

If you’re curious whether your normal browser is using IPv4 or IPv6, there is a cool browser plugin for Firefox called “IPvFox”, and one for Chrome called “IPvFoo”, that will show a “4” or “6” in the address bar. Sometimes, it will show a combination, if the web page content is coming from a mixture of sources.

I wanted to see if there was a way to get IPv6 to my home network, even when I am sitting behind my neighbor’s router.

Gogo6 / Freenet6

I dug around a little, and I found that there are other tunnel brokers that use different schemes of encoding their IPv6 packets and ferrying them to their point of presence. I found one called “Freenet6” that uses a scheme called TSP (on a TCP/IPv4 socket) to get things up and running, and then it encapsulates the IPv6 packets inside UDP/IPv4 packets. This means you can use Freenet6 when you are behind a more restrictive router like your neighbor’s, or at a hotel or a conference).

Freenet6 was not too hard to set up, but it was confusing and a bit annoying.

First, TSP needs a software client on your router. You can download one client from the Freenet6 web site. But I dislike running someone else’s client software as root on my systems. So instead I used the open source “gogoc” that is packaged for Debian.

Second, when you first connect, it might complain about keys, because you’re connecting to “authenticated.freenet6.net”, but you end up talking to “montreal.freenet6.net”. You can get around that my setting CHECK_KEYFILE=”no” in /etc/default/gogoc. I’ll want to revisit this later after things are up and running.

Third, I had a hard time authenticating. After trying many things, I discovered that there are TWO unrelated usernames and passwords that you’ll need.

• The first username/password is for the gogo6 web site. Your username there will be your email address. This is only used for the web site and forums.
• The second username/password is actually used by the gogoc client. To get this, you have to sign up for a Freenet6 Pro account. This account is free, but you have to send an endorsement on Twitter to get it… and this is done in the most annoying way. You click on “Pay with a Tweet or Facebook”, which takes you to a site called paywithapost.de. It wants you to grant access to their Twitter app called “Pay with a Tweet Social Payments”. That’s right… not only do you have to tweet, but you have to install a Twitter app that has access to your account. I used a special “shill” account that I have for just this sort of thing, and then I immediately revoked access to that app.

So, configuration and annoyances behind us, I was able to run the open source “gogoc” client, and it assigned an IPv6 address to my router (which advertised it to the other computers in my house), and now my entire home network has IPv6 access again.

I am looking forward to trying Freenet6, and seeing how it compares to the Hurricane Electric tunnel that I am used to.

I’d also like to shout out to my neighbor, who was nice enough to let us mooch off of his internet service until AT&T gets their act together.