Welcome IPv4 user

DNS in IPv6 land

Many of the experienced networking people that I speak to about IPv6 have one major complaint: "IPv6 is rubbish - I would never be able to type an address that long out of my head"

It is true that many network technicians and engineers make regular use of IPv4 literals in their daily lives. My view is that if you are typing the IP address then - YOU ARE DOING IT WRONG!

IPv6 may well be the push that is required to get many lazy networking professionals to implement proper DNS on their networks. A properly set up DNS infrastructure even on a home LAN can be a life saver and it save a lot of time in the long run.

DNS tips for IPv6 survival:

  • DNS everything - choose an easy to remember hostname for every device on your network. Every PC, server, router, wifi AP and IP capable device should have a hostname that you can add to your zonefile.
  • Choose your best IP for DNS. DNS should be the only thing that you ever have to manually configure on a device. Choose the shortest and easiest available IP address for your DNS server. If you are running a large network then choose 3 or 4 prefixes that you reserve for DNS anycast resolvers. That way you avoid confusion by using the same DNS server IP throughout the whole network.
  • Keep it local. If you don't want to do full DNS infrastructure then add it to your local DNS resolver. Many home routers and gateways have a 'hosts' facility that allows you to add DNS entries that are visible only within your local network.

and finally

  • Make proper use of 'search domains'. Most IP devices have a config option called a 'search domain' or sometimes just 'domain'. This is the home domain of the host and is appended to any DNS query when it is first looked up. This means that you can use the DNS name 'myserver' and it automatically gets expanded to 'myserver.example.com' for you. This is a huge time saver since your DNS name is now in fact shorter than even the IPv4 address of a host.

Getting together some IPv6 tools

In the same way as IPv4 you will need a toolbox in order to function efficiently.

The two most common tools will be ping and traceroute. Under Ubuntu you can access both of these via the command line as 'ping6' and 'traceroute6'. I personally prefer 'mtr' (MyTraceroute) to give me a continuous view of latencies and paths of packet. 'mtr' supports both IPv6 and IPv4 and will default to IPv6 when available. It is possible to force and IPv4 trace using the '-4' switch.

The most interesting IPv6 tool I have yet come across is the ShowIP plugin for firefox. This tool sits in the status bar of your browser and reports the IP address of the web server that you are visiting. This on its own is extremely useful. IPv4 addresses are displayed in red but the real gem is when you are connecting to an IPv6 website the IP is reported in green.

This plugin is quite useful to determine if your browser and the website are IPv6 aware. Run it in your browser for a few weeks and you may well be rather pleasantly surprised by the numerous websites that have quietly added IPv6 support to their servers.


PING6 blog is reachable on IPv6

I've finally finished getting apache working with IPv6 and vhosts. It has been a little bit of a challenge under cPanel but I will talk more about that at a later date.

For right now though - PING6 is reachable over IPv6! Which should be a pre-requisite for running a blog about IPv6 ;-)

IPv6 is now coming into the main stream. I'm using the IPv6 versions of Google, YouTube, Facebook and numerous other sites daily. My mail comes in and out over IPv6 and hopefully soon I will be able to function normally on the Internet with only an IPv6 connection thanks to NAT64. More on that in the coming months.


Getting Connected to IPv6

The first logical step to beginning your IPv6 journey is getting connected. No South African ISPs yet provide end user connectivity that is natively IPv6 enabled but IPv6 was designed to handle this very problem. There are a wide variety of standards that have been developed to allow you to create tunnels over the current IPv4 network of your service provider to get you to the next generation IPv6 Internet.

These IPv6-over-IPv4 tunnels have to terminate on a tunnel server or router that is connected to both the IPv4 and IPv6 Internet so that they can route traffic between the networks. There are many freely available tunnel services but none of these are currently provided in South Africa. This means that all your IPv6 traffic has to go via a tunnel server located usually in Europe or the US. This will add an additional 200-300ms latency to all your connections but it is usually not of concern when you are accessing international websites or Internet services.


This innovative tunneling protocol is potentially the easiest to get working on any host that has a public IPv4 address. The four octets (the bits between the dots) of the IPv4 address are converted into hex and then used to automatically calculate your new IPv6 address. Your ISP then automatically connects you with your closest 6to4 gateway server through a technique called anycast. 6to4 addresses are easy to identify since they all begin with:


The values of ww, xx, yy and zz are calculated as follows:

IPv4 Address:                192.0  .2  .12
Hex Equivalent of octets:    C0  00  02  0C

IPv6 Prefix:              2002:C000:020C::/48

Note that each IPv4 address maps to an entire prefix (or subnet) of IPv6 addresses - many thousands of IPv6 addresses in fact. This means that you could use 6to4 on your ADSL router and then assign globally unique IPv6 addresses to each device connected to that router even though they only have private IPv4 addresses.

A number of short scripts are availble for many common types of systems that will automatically configure a 6to4 connection on your host.


If you have a single PC that you want to connect to IPv6 and you are behind a NAT gateway (like a typical cheap ADSL router) then 6to4 will not work since you do not have a public IPv4 address on your PC. You need to tunnel your IPv6 traffic in a way that will pass freely through your NAT gateway. This is typically done through UDP tunneling.

A number of so-called tunnel brokers exist that can provide this service. You load their software onto your PC and then it creates a connection to the tunnel broker to provide you with IPv6 connectivity. This is doneĀ  in a similar way to VPN software.

SixXS is one popular provider of this tunnel broker service. The easiest service to get connected with is however Go6. You simply install their tunnel setup software and you can be connected to the IPv6 Internet in a matter of minutes. You can then register on their website and obtain a fixed IP. This means that no matter where you connect from you will always have the same IPv6 address.


The best option to choose if you want to connect a server with a fixed IP to the IPv6 Internet is 6in4. This provides you with a statically configured tunnel with a known endpoint that you can reliably control. The best provider of 6in4 connections is the Hurricane Electric Tunnelbroker service. They can provide you with a fixed IPv6 over IPv4 tunnel to one of their many tunnel servers around the world. You are free to choose the server that has the least latency and they will assign you a large prefix of IPv6 addresses on request via their web interface.

Other options

If you are still looking for options then why don't you look at how Vista automatically tunnels IPv6 traffic over Teredo.

Better still - phone up your ISP and ask them when they are going to provide you with IPv6 connectivity directly!