27 Feb 2011

How to get IPv6 on your home network

It has been almost seven years since I last played with IPv6 (link, link). There has been lots of talk of IPv6 lately, and the company I work for has done some real-world IPv6 testing and deployment (check out Tore's IPv6 page: http://fud.no/ipv6/).

Since my local ISP has not deployed IPv6, and probably will not for a long time - I went looking for a "IPv6 tunnel broker". A tunnel broker enables you to tunnel IPv6 traffic over IPv4 to a IPv6 gateway (called "PoP").

So, which tunnel broker to choose from? Wikipedia give me a lot of choices. Several colleagues tipped me of SixXS -- their service is stable and professional, you get a /48 network and they have a PoP here in Oslo they said. Easy choice. 

First some paperwork:

1) First, apply for an account at SixXS:


Be patient - this can take some time since it require manual (human) verification. It took me 8 hours from I applied to my account was accepted.

2) Once you get your username and password, log into the web-interface, and proceed to request a tunnel. Choose "Dynamic NAT-traversing" as type of tunnel. Choose your neares POP, and submit. This process is automated, and it took approx 30 minutes before my request was accepted.

3) When 2) is complete - you have ONE routable IPv6 address. Since we need more than that, we proceed to request a subnet from SixXS webpage. 30 minutes later, my subnet was allocated. 

So I've received from SixXS the following information (not actual IPv6 addresses):
A) IPv6 gateway at SixXS: 2001:FFFF:FFFF:FFF::1/64
B) My local IPv6 gateway: 2001:FFFF:FFFF:FFF::2/64
C) My allocated IPv6 subnet, which is routed to B): 2001:FFFF:EEEE::/48

Next, we're ready to configure/install: 

4) First, install a helper daemon that take care of your IPv6 tunnel automatically. It's called AICCU (Automatic IPv6 Connectivity Client Utility):


On Debian/Ubuntu install it by:

  $ sudo apt-get install aiccu

Enter your SixXS username and password when asked for it. You tunnel interface will be named "sixxs" and enabled (global IPv6 address in red):

  $ ifconfig sixxs
  sixxs     Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 
            inet6 addr: fe80::14d8:eeff:142:2/64 Scope:Link
            inet6 addr: 2001:FFFF:FFFF:FFF::2/64 Scope:Global   
            RX packets:0 errors:0 dropped:0 overruns:0 frame:0
            TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:500
            RX bytes:0 (0.0 B)  TX bytes:144 (144.0 B) 

5) Test your IPv6 connection:

  $ ping6 ipv6.google.com
  PING ipv6.google.com(2a00:1450:8004::93) 56 data bytes
  64 bytes from 2a00:1450:8004::93: icmp_seq=1 ttl=52 time=42.5 ms
  64 bytes from 2a00:1450:8004::93: icmp_seq=2 ttl=52 time=44.0 ms
  64 bytes from 2a00:1450:8004::93: icmp_seq=3 ttl=52 time=43.7 ms

Good, we have IPv6 connectivity, but only from one host. We want IPv6 on our whole home network.

6) Since we're given a /48 network, it enables us to have 65536 /64 networks. Which should suffice for most needs. Our network architecture would look like this when complete:

We configure our IPv6 gateway (vallhall-r6) to route IPv6 traffic for our local network. First we need to assign a IPv6 address on the actual interface facing our network. This will be our IPv6 gw address for our network:

  $ sudo ifconfig eth0 inet6 add 2001:FFFF:EEEE::1/48
  $ ifconfig eth0  
  eth0      Link encap:Ethernet  HWaddr 52:54:de:ad:be:ef 
            inet addr:  Bcast:  Mask:
            inet6 addr: fe80::5054:ff:feb6:beef/64 Scope:Link
            inet6 addr: 2001:FFFF:EEEE::1/48 Scope:Global
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:16849 errors:0 dropped:0 overruns:0 frame:0
            TX packets:13394 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000
            RX bytes:7336450 (7.3 MB)  TX bytes:7082583 (7.0 MB)

Make it permanent by adding it to:

  # cat /etc/network/interfaces
  iface eth0 inet6 static
      address 2001:FFFF:EEEE::1      
      netmask 48
      endpoint 2001:FFFF:FFFF:FFF::1  # your SixXS gw
      ttl 64

7) Make sure our gateway route IPv6 traffic:

$ sudo sysctl net.ipv6.conf.all.forwarding=1
  net.ipv6.conf.all.forwarding = 1

Make it permanent, by adding it to:

$ cat /etc/sysctl.conf

8) You can now configure your network equipment with static IPv6 addresses. Since IPv6 uses hex (and thereby the letters A-F), some words/sentences can be embedded in these addresses:

  baba, babe, bade, bead, beef,
  cede, dace, dada, daff, dead,
  deaf, deed, face, fade, feed, ...

This way, your file-server can have an address like:


go wild..

9) We don't want to configure all our host manually, so we need some kind of auto-configure. While IPv6 have DHCPv6, (like IPv4's DHCP), a more elegant solution is to use "stateful address autoconfiguration".

The host configure themselves by acquiring a prefix from a local IPv6 router, and combined with the local MAC address, creates a IPv6 address (router advertisements + MAC address of interface = IPv6 address).

We use radvd for sending these "router advertisements". Install and configure:

  $ sudo apt-get install radvd
  $ cat /etc/radvd.conf
  interface eth0 {
      AdvSendAdvert on;
      MinRtrAdvInterval 3;
      MaxRtrAdvInterval 10;
      prefix 2001:FFFF:EEEE:aaaa::/64 {
          AdvOnLink on;
                  AdvAutonomous on;

                  # After testing, can be set to 14400
                  AdvPreferredLifetime 30;
                  # After testing, can be set to 86400
                  AdvValidLifetime 30;

Start radvd:

  $ sudo service radvd restart
  Stopping radvd: radvd.
  Starting radvd: radvd. 

10) Excellent! Radvd will now send IPv6 prefix periodically (or when requested by a new client) to your network. All IPv6 capable host should now automatically configure themselves with a IPv6 address.

You should now be able to access IPv6 enabled hosts. Try for example: http://ipv6.google.com 

11) A final warning and advice: ADD A FIREWALL on your IPv6 gateway! Since IPv6 don't use NAT, every hosts that use IPv6 is directly accessable from the Internet. This is a good thing, but it also expose all your IPv6 enabled hosts and their services.

A good starting point for IPv6 firewall:


Good luck!

Troubleshooting tips:

I) Dump IPv6 traffic using tcpdump:

  # tcpdump -i eth0 -vv ip6 or proto ipv6

II) Show your IPv6 routing table:

  # ip -6 r s

II) Check radvd messages

  # radvdump

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