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Getting (fast) IPv6 at home


I value IPv6 access as quite important, however T-Mobile Thuis doesn't offer any official form of IPv6 on their network at this time. I looked into various options to get decent IPv6 for my home network:

  • 6to4
  • tunnelbroker
  • VPN based access


6to4 is a deprecated form of IPv6 access, but something that would work for any connection with a fixed IPv4 address. Configuring 6to4 on OpenWRT is quickly done, and it was easy to delegate a /64 subnet to my local network. 6to4 however results in a quite slow connection (of around 10 to 20 megabit), and reachability was spotty at best. tunnelbroker

Upto a couple of years ago there used to be various public tunnelbrokers for 6in4 tunnels, and I used the tunnels for almost 10 years myself, however, almost all public tunnel-services seem to have shut down over the years. Only's tunnelbroker seems to be alive.

I have used a couple of tunnels throughout the years, and while they work fine in general, they seem quite limited in available bandwidth. This became even worse as shutdown, as most sixxs users migrated to

Configuring OpenWRT to use a tunnel is quite easy, just a matter of copy/pasting the values from your account into OpenWRT's webinterface and providing credentials for the dynamic updating of the tunnel.

I did some speed-tests and these confirmed my experience, I seemed to be limited to maybe 20mbit, which is a bit low when using a 700+ mbit connection, but this is to be expected for a free service. If your needs are limited, is a good and free solution.

VPN based access

The third and final method of getting IPv6 that I tried was tunneling over IPv4 to my own server in a public datacenter. At that server (hosted at Hetzner) I have a /56 of IPv6 space, This is not standard, but available on request, and you get a /64 standard with every server or VPS.

I configured wireguard on OpenWRT (client) and my server in the datacenter, and route a /60 subnet of IPv6 space to my home-network. This range can then be split further for a couple of subnets. The remainder of the /56 can be used for some more VPN's and tunnels.


Using the Wireguard VPN and testing speed on IPv6 I could easily get over 200mbit per second and I have even seen it hit 500mbit.


  • Try and get IP-TV working, though this doesn't have much priority for me
  • Cancelling voice and tv-subscriptions before the discount runs out :)

OpenWRT Config

Various bits of relevant configuration for OpenWRT:

The configuration of the switchports:

config switch
  option name 'switch0'
  option reset '1'
  option enable_vlan '1'

config switch_vlan
  option device 'switch0'
  option vlan '1'
  option ports '1 2 3 4 6t'
  option vid '1'

config switch_vlan
  option device 'switch0'
  option vlan '300'
  option vid '300'
  option ports '0t 6t'

config switch_vlan
  option device 'switch0'
  option vlan '640'
  option vid '640'
  option ports '0t 6t'

config switch_vlan
  option device 'switch0'
  option vlan '100'
  option ports '0t 6t'
  option vid '100'

Configuration of the Wireguard VPN for IPv6 tunneling

config interface 'WG6'
  option proto 'wireguard'
  option private_key '<wireguard-private-key-base64>'
  list addresses '2001:xxxx:xxx:xxx::3/60'

config wireguard_WG6
  list allowed_ips '::/0'
  option endpoint_host 'ipv4-of-wireguard-server'
  option endpoint_port 'wireguard-portnumber'
  option persistent_keepalive '25'
  option description 'Wireguard-ipv6-tunnel-name'
  option public_key '<public-key-of-wireguard-server-in-base64>'
  option route_allowed_ips '1'

config route6
  option interface 'WG6'
  option target '0::/0'
  option gateway '2001:xxxx:xxx:xxx::1'

T-Mobile Thuis (fiber) with a custom router

I have been using as my ISP for a few years now, since getting fiber-to-the-home, but Tweak doesn't have their own (non-KPN (incumbant dutch telco)) infrastructure in my area. This means they are limited in offering products provided by KPN, at prices mostly dominated by what they have to pay KPN to get access to the last-mile. In area's where they do have their own fiber infrastructure they can offer gigabit connections at very nice prices (less then €400 per year) and 10-gigabit even, but this is a bit overkill, especially since traffic is then quite limited :)

T-Mobile Thuis (which used to be Vodafone Thuis, but had to be split-off from Vodafone due to anti-compete measures) does have it's own infrastructure in my area, which means they can provide their own networking products. This translates into getting a symmetrical 750 mbit connection for €40,- per month (Sold as €50,- with a permanent 10,- discount). It can also include voice and TV-services, but these cost extra, and would only with if you let T-Mobile control your network by using their router.


Sadly they still don't provide any form of native IPv6 connectivity, and I'm not too fond of letting ISP's control my routers and internet-infrastucture, so I looked into ways to get a fast and affordable connection whule using my own router, preferably running OpenWRT.

After some research on the and T-Mobile Thuis web forums I was sure that it wouldn't be too hard to get a fast internet-connection on T-Mobile Thuis using my trusty OpenWRT routers. The requirements basically come down to:

  • Some way to connect to the fiber-connection
  • A fast enough OpenWRT based router that can handle gigabit speeds
  • Support for VLAN's

I initially used a RouterBoard RB750Gr3, since I was already using that as a router for my Tweak connection, but I also had a few Edgerouter ER-X's around. Both routers basically are the same chipset, but with slightly different peripherals. The RB750 has a low amount of flash, but USB and MicroSD ports, so you can add external storage, the ER-X has no USB or MicroSD, but has 256MB of built-in flash, which is more then enough for everything you might want to install on it.

Both routers would be more then sufficient and powerful enough to route a gigabit connection, as they have 256MB of RAM, and a quad-core Mips24 800Mhz cpu. In the end I swapped out the RB750 for the ER-X, since I had a few of those and only one RB750 and would have no use for the USB port on the router.

Installing OpenWRT 18.06.1 is outside of the scope of this article, but I've written about installing it in an earlier post, and documentation is on the OpenWRT wiki

Connecting to the fiber

The first step is finding some way to connect the router to the fiber. There are basically 2 methods to do this:

  • Get a router with an SFP port,and use the SFP module that is provided by T-Mobile, as their own router also uses an SFP-port. This is most useful when the T-Mobile/Guidion mechanic has set-up your connection.
  • Use a media-converter. In my case, there was already a media-converter present, since this was the solution used by my two previous ISP's. This box connects to the fiber, and outputs the conneciton over a RJ45 connection. I used this connection to hoop up to the OpenWRT routers WAN port using a CAT5e cable.

If you want to go for the SFP method, be sure to get a router with SFP-ports, like the ER-X-SFP or the HEX_S

VLAN Configuration

T-Mobile Thuis uses a few different VLAN's, but for our use we only need to use the regular internet VLAN, which is vlan 300. Besides this vlan there is also vlan 100, which is used for T-Mobile's management and vlan 640, which is used for TV.

Configure the WAN port or port that's used for connecting to T-Mobile with the 3 tagged vlan's


The internet vlan (300) will give you a public IPv4 address using a DHCP-request. This will also be the default gateway. The Management-lan (100) wil also respond to DHCP-requests, but only return adresses in ip-space. There is some traffic on this network, but I haven't looked into it too much yet.


Posts on various forums informed me that IP-TV is normally configured on the 640 vlan. I myself don't use much TV, so I haven't done any configuration yet. T-Mobile also lets you use TV-Anywhere, which is a mobile application (IOS/Android) for streaming TV on any internet-connection, so this can be used as a zero-configuration alternative. I might update this post or publish a new one when I get TV-Streaming working, but I'll probably cancel the TV and voice subscriptions before too long, I only took them because it was cheaper with then without (the first 6 months).


  • Try and get IP-TV working, though this doesn't have much priority for me
  • Cancelling voice and tv-subscriptions before the discount runs out :)

OpenWRT Config

Various bits of relevant configuration for OpenWRT:

The configuration of the switchports:

config switch
  option name 'switch0'
  option reset '1'
  option enable_vlan '1'

config switch_vlan
  option device 'switch0'
  option vlan '1'
  option ports '1 2 3 4 6t'
  option vid '1'

config switch_vlan
  option device 'switch0'
  option vlan '300'
  option vid '300'
  option ports '0t 6t'

config switch_vlan
  option device 'switch0'
  option vlan '640'
  option vid '640'
  option ports '0t 6t'

config switch_vlan
  option device 'switch0'
  option vlan '100'
  option ports '0t 6t'
  option vid '100'

Sig-I/O now 9 years old, debian-lts sponsor for 3

This week marks the 9th year in Sig-I/O's existance. Looking back over the past nine years shows a nice growth in the number of clients and a collection of interesting assignments Sig-I/O has been involved in.

While the services that Sig-I/O provides have shifted somewhat over these 9 years, some have also remained the same, with some clients already with us from the very beginning. The past few years have been mostly about Managed Hosting, Linux-, Ansible- and Security-Consulting and since a few years also Training, via a partnership with IT-Gilde which has been going steady for 3 years now.


This month also marks the 3rd complete year that Sig-I/O has been a sponsor of the Debian LTS project. This sponsorship has also been renewed for the coming year. The Debian LTS project could use some more sponsors, so if your organisation uses Debian servers extensively, it might be beneficial to sponsor them. Debian LTS will support Debian 7 until May of 2019, and will then continue with LTS support for Debian 8 into the 2020's

The next few years will undoubtedly bring many more interesting challenges and opportunities.

Migrated website to a static site powered by Nikola

As you might have noticed if you visited my site before, the entire look and feel has been changed. The site is now powered by the Nikola static-site-generator. The most-recent articles have been migated over, the older articles from the previous website will be restored when they are still relevant.

I had been thinking about using a Static-Site-Generator before, but wordpress was working quite well for me. Recently however I managed to lose my wordpress database, and this privided me with a good opportunity to re-do the site using Nikola.

I'm still getting the hang of writing reStucturedText, and still need to update some pages, but at least the website is back from the abyss. Most articles have been restored from the WayBack-Machine operated by

Using Nikola

In case you are interested in using a static-site generator, this is my workflow:

  • Stream some nice relaxing music
  • Install python3, setup a virtualenv for Nikola
  • Pip install "Nikola[Extras]"
  • nikola init mywebsite
  • Version the newly created site in git
  • Make some changes to the config-file
  • Choose and download a theme
  • Write some posts and pages (nikola new_post -e)
  • Git add all your changes, push to a remote server
  • Nikola build
  • Rsync the output directory to a webserver

OpenWRT/LEDE On a Routerboard RB750Gr3 (Hex3)

The Routerboard RB750Gr3 (aka Hex3) is a nice and very affordable (~$60) hardware platform based on the MediaTek MT7621AT. It features gigabit ethernet ports, and a relatively fast multi-core CPU. However, out of the box it runs RouterOS. While this is a feature-full platform, I found configuration difficult and not very pleasant. Hoping that a build of OpenWRT/LEDE would soon become available, I bought an RB750Gr3 a couple of months ago.

A build became available, but it couldn’t be flashed on the RB750Gr3 without external hardware like a bus-pirate. But this has recently changed, and it’s now possible to TFTP boot a LEDE runtime, which allows access to write to the flash/mtd. Using this method it’s now possible to install OpenWRT/LEDE and upgrade uboot on the device without external hardware.

The OpenWRT site documents this procedure nicely, however, it’s still quite a lot of work to build all the required images and files. So I’ve deciced to host the images that I’ve created here, so other people can skip this rather tedious step of building the image.

The files can be found on

Please update factory.bin with your own MAC address at offset E000. Currently it’s set to 64:D1:54:AA:BB:CC

  • You can then netboot/tftpboot using the file ‘vmlinux-initramfs.elf’ (boot the RB750 and hold RESET until the leds stop flashing)
  • Wait for the system to come up on
  • Login as root
  • Copy the factory.bin uboot.bin uboot-env.bin and lede-17.01.2-ramips-mt7621-rb750gr3-squashfs-sysupgrade.bin to the system (in /tmp for example)
  • mtd write (without reboot) the 4 files to the relevant partitions (cat /proc/mtd to see the names/devices)

Monitoring S.M.A.R.T. attributes in Nagios/Icinga

One of my customers is using various (Samsung) SSD’s in their servers, and the first of these have started reaching their end-of-life. SSD’s have a somewhat different failure scenario then spinning metal disks, so monitoring their life-expectancy can be interesting.

Besides just logging and graphing the SMART attributes, it is also handy to have some alerting on when certain thresholds are crossed. To do this, I’ve written a simple nagios/icinga script which will alert on interesting SMART attributes, and will also calculate the percentage of total guaranteed writes on the SSD’s. Since the guaranteed TBW value will differ between various SSD vendors and product-ranges, this value needs to be specified on the command-line by the user.


I’ve integrated this check-script into my normal monitoring-scripts, but it can off-course also be used as a stand-alone tool. If has options to specify the device to smartctl, so disks behind raid-controllers can also be monitored.

The script can be found in my sysadmin repository on github: check_ssd_attribs

Sig-I/O joins up with ITGilde Coöperatie

Today, september 2nd 2015 Sig-I/O Automatisering has joined the ITGilde Coöperatie


By joining ITGilde Coöperatie the customers of Sig-I/O Automatisering can make use of the knowledge and skills of a large (~50) group of highly skilled freelance Unix/Linux specialists.

The following (dutch) article was posted on the ITGilde website:

Vandaag verwelkomt ITGilde Mark Janssen als 49ste lid van ITGilde. Naast
ITGilde is Mark actief bij de NLUUG en RevSpace . Het motto van Mark
is: “over 5 minuten is het opgelost”.

De reden voor Mark om aan te sluiten bij ITGilde is een kwalitatief
hoogwaardig netwerk met een hoge frequentie van vakgerelateerde
bijeenkomsten; gericht op Linux/Unix ondernemers.

Daarnaast werkt Mark meer dan fulltime en wil toch meer klanten kunnen
helpen dan hij nu aankan. ITGilde is daar de oplossing voor: “ik kan
mezelf maar 1 keer inzetten maar met ITGilde beschik ik nu over een pool
van goede technische Unix/Linux specialisten!”

Welkom Mark!

Read passwords from the 'pass' passwordstore into ansible

Ansible is a great orchestration-tool, and while it has it’s own secure password storage system (Vault), I prefer to use ‘pass’ from

There is no specific ‘pass’ plugin for ansible, but using the ‘pipe’ lookup plugin works quite well

  - name: Debug
      debug: msg={{lookup('pipe', 'pass some/password/i/need') }}

This can then be used to store API keys, passwords for various accounts, or other information that needs to remain secret while still being able to share and version your ansible plays.

Update 2017: There is now a passwordstore lookup-plugin for ansible

Tenshi log monitor now supports Redis inputs

Sig-I/O has been using Tenshi for quite a while, as it’s one of the easier and more flexible log monitoring tools available. It’s also quite light-weight and has only a few perl modules as requirements.

However, tenshi has been showing it’s age, as it only supported syslog, flat files or fifo’s as inputs. These days json based logging with graylog2, logstash or other tools seems to be all the rage.

Since we needed to setup a new log monitoring solution for a customer and they didn’t have a central syslog server, but were using logstash and redis, it was a perfect time to add Redis support to Tenshi.

Patching a Redis input to Tenshi turned out to be quite easy using the perl Redis module. The patch has been sent to the upstream developer and will most likely be included into a next release.

For those who can’t wait, and want to try out the Redis support, the code can be found at my github repository in the ‘redis’ branch of tenshi

Installing php 5.4 or 5.5 on CentOS 6.x / RHEL 6.x / SL 6.x

There are many posts on the internet about people wanting to install a newer PHP release on their EL6 boxes. Most of these posts will tell you to either install the ‘remi’ repository, or packages from ‘webtatic’. However, there is a newer, and in my opinion better, method now. Software Collections

Redhat has created the concept of software collections, in which they can provide newer or additional packages to the base OS. These packages come with a more limited support package, but they are at least a somewhat standardised way of installing additional functionality without impacting the base OS. Red Hat Enterprise Linux 6

In RHEL systems, collections can be enabled with:

  • Enable the redhat collections channel
    • rhn-channel –add –channel=rhel-x86_64-server-6-rhscl-1
  • Then install software from it:
    • yum install php54-php

More info can be found on CentOS 6 / SL 6 / OEL 6

For the community EL6 systems, the following procedure can be used:

The list of available collections and their package-url’s can be found on