Blog Entries tagged ipv6
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Calculating the automatically assigned IPv6 adress given prefix and MAC

Published: 2009-02-04 18:36 UTC. Tags: network ipv6

Today I had the need to calculate the automatically assigned IPv6 adress I knew a host probably had since the network has a router advertisment daemon.

I knew the network prefix and the hardware address (MAC/EUI-48). I suspected ipv6calc could probably do the job, but I had great trouble finding out how. I'm sure the commandline syntax for ipv6calc makes sense once you get used to it..

Anyway, here's how, for my own and your future reference:

ipv6calc --in prefix+mac --action prefixmac2ipv6 2001:aaaa:bb:cccc::/64 AA:BB:CC:DD:EE:FF --out ipv6addr

IPv6 prefix as well as MAC obfuscated to protect the innocent.

Relevant links:


QNAP TS-109 II - First Impressions

Published: 2008-12-02 20:06 UTC. Tags: linux review ipv6 turbostation

I bought a second hand Squeezebox the other day. The Squeezebox must read its files from a server running Squeezecenter, and since I don't want my workstation running all day (it's consuming energy. I'm trying to be environmentally friendly when I can), I had to find a low-power alternative.

I have been thinking about getting some kind of server running at home for a while. There are other things I want it to do as well:

  • Keep a SixXS IPv6 tunnel up, and route an IPv6 subnet for home.
  • Be able to Wake-on-LAN my main workstation.
  • Get better network throughput than from my stupid 3com NAT box.
  • Etc, etc..

After some consideration, I bought a QNAP TS-109 II. It has a 500MHz ARM processor, 256Mb of RAM and consumes 14Watts of energy when active, 6,6W when not. That's quite OK. I bought a WD Caviar Green 500Gb hard drive for it. That drive is supposed to be quiet and energy efficient.

Another killer fact about the QNAP is that the upcoming Debian Lenny will have official support for all TurboStation models from QNAP. It's even listed as a press release on QNAP's webpage. The installation link from the press release doesn't seem to work anymore, though. The Debian on QNAP TS-109 pages are very helpful, though.

The QNAP + hard drive arrived today, and I unpacked and assembled the two (very easy), plugged it in, found its IP address from the list of DHCP entries in my NAT box, and tried to connect to it via a web browser on both port 80 and port 8080.

Unfortunately, I was met by a message in several languages basically telling me that "This box is not initialized, do what the manual says". And the manual says that you need a Windows computer to initialize the TS-109.


I don't own a Windows computer!

Fortunately, my girlfriend has an XP box which I could use to run the "QNAP Finder" to install the QNAP. Still, I find this irritating. There's support for Mac as well, but I don't have any Mac neither.

I'm sure there's some way of initializing the device without Windows, but that might require lot's of knowledge on the RPC protocol used to talk to the device. Presumably, it's some kind of RPC over HTTP, as the only ports the device has open at initial startup is 80 and 8080.

Navigating around in the menus for a while, I was not surprised to see that running Debian on the machine would be the best option for me. Specifically:

  • There's no support for NFS on the TS-109 II. You need the TS-109 II Pro for that.
  • There's no network routing support in the standard firmware, and that's not surprising - this is a NAS box afterall. But with Linux and it's VLAN support and iptables, it should work well. We'll see about that... :-)
  • The configuration can't be easily handled via Puppet when running the standard firmware. That's something I do for other servers I manage.

Anyway, I think I'll be happy with this box. I might add an external eSATA enclosure later to provide backup of the stuff I keep on the QNAP. We'll see. Backing up stuff to Amazon S3 is another option.


Enabling IPv6 in Dovecot and Postfix

Published: 2008-11-29 20:20 UTC. Tags: linux network ipv6

I realized after some testing that neither Postfix (my MTA), nor Dovecot listened to IPv6 by default. In both cases, enabling IPv6 was easy.

(This is where I found out that my algorithm for getting parts of an entry and showing it on the front page doesn't work that well.. so therefore, this text has been added, as it works as a workaround).


Set the inet_protocols parameter in /etc/postfix/


The default value is ipv4.


Set the listen parameter in /etc/dovecot/dovecot.conf:


At least on Linux, this will make Dovecot listen to both IPv4 and IPv6. Setting the value of listen to *, will make it listen only to IPv4.


My apache server happily picked up the presence of an IPv6 interface after a restart. This is probably due to the fact that I have a the following in my Apache configuration:

0 comments. - now via IPv6

Published: 2008-11-29 19:19 UTC. Tags: world wide web network ipv6

I have been intrigued by IPv6 for a long time. The worldwide challenge of smoothly switching from IPv4 to IPv6 without end-users noting the switch is fascinating.

Getting IPv6 adresses for clients or servers where the IPv4 network provider doesn't provide IPv6 natively is very easy - there are several tunnel brokers. I have two tunnels at SixXS - one to get IPv6 at home, and one to get IPv6 to my Slicehost machine (the one serving you this blog post). DNS AAAA entries have been added, so with IPv6 support on your client, you can now reach via IPv6.

However, IPv4 is still required for access, because the slicehost DNS servers that I'm using are reachable via IPv4 only.

To ensure a high nerd factor of, I have also modified django to add a footer to the end of all pages with a happy message if you're running IPv6 :-).