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  13  <h1>
  14      <a href="http://people.skolelinux.org/pere/blog/">Petter Reinholdtsen</a>
  15
  16  </h1>
  17
  18 </div>
  19
  20
  21     <h3>Entries tagged "mesh network".</h3>
  22
  23     <div class="entry">
  24       <div class="title">
  25         <a href="http://people.skolelinux.org/pere/blog/Teaching_vmdebootstrap_to_create_Raspberry_Pi_SD_card_images.html">Teaching vmdebootstrap to create Raspberry Pi SD card images</a>
  26       </div>
  27       <div class="date">
  28         27th October 2013
  29       </div>
  30       <div class="body">
  31         <p>The
  32 <a href="http://packages.qa.debian.org/v/vmdebootstrap.html">vmdebootstrap</a>
  33 program is a a very nice system to create virtual machine images.  It
  34 create a image file, add a partition table, mount it and run
  35 debootstrap in the mounted directory to create a Debian system on a
  36 stick.  Yesterday, I decided to try to teach it how to make images for
  37 <a href="https://wiki.debian.org/RaspberryPi">Raspberry Pi</a>, as part
  38 of a plan to simplify the build system for the FreedomBox project.
  39 The FreedomBox project already uses vmdebootstrap for the virtualbox
  40 images, but its current build system made multistrap based system for
  41 Dreamplug images, and it is lacking support for Raspberry Pi.</p>
  42
  43 <p>Armed with the knowledge on how to build "foreign" (aka non-native
  44 architecture) chroots for Raspberry Pi, I dived into the vmdebootstrap
  45 code and adjusted it to be able to build armel images on my amd64
  46 Debian laptop.  I ended up giving vmdebootstrap five new options,
  47 allowing me to replicate the image creation process I use to make
  48 <a href=http://people.skolelinux.org/pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html"">Debian
  49 Jessie based mesh node images for the Raspberry Pi</a>.  First, the
  50 <tt>--foreign /path/to/binfm_handler</tt> option tell vmdebootstrap to
  51 call debootstrap with --foreign and to copy the handler into the
  52 generated chroot before running the second stage.  This allow
  53 vmdebootstrap to create armel images on an amd64 host.  Next I added
  54 two new options <tt>--bootsize size</tt> and <tt>--boottype
  55 fstype</tt> to teach it to create a separate /boot/ partition with the
  56 given file system type, allowing me to create an image with a vfat
  57 partition for the /boot/ stuff.  I also added a <tt>--variant
  58 variant</tt> option to allow me to create smaller images without the
  59 Debian base system packages installed.  Finally, I added an option
  60 <tt>--no-extlinux</tt> to tell vmdebootstrap to not install extlinux
  61 as a boot loader.  It is not needed on the Raspberry Pi and probably
  62 most other non-x86 architectures.  The changes were accepted by the
  63 upstream author of vmdebootstrap yesterday and today, and is now
  64 available from
  65 <a href="http://git.liw.fi/cgi-bin/cgit/cgit.cgi/vmdebootstrap/">the
  66 upstream project page</a>.</p>
  67
  68 <p>To use it to build a Raspberry Pi image using Debian Jessie, first
  69 create a small script (the customize script) to add the non-free
  70 binary blob needed to boot the Raspberry Pi and the APT source
  71 list:</p>
  72
  73 <p><pre>
  74 #!/bin/sh
  75 set -e # Exit on first error
  76 rootdir="$1"
  77 cd "$rootdir"
  78 cat &lt;&lt;EOF > etc/apt/sources.list
  79 deb http://http.debian.net/debian/ jessie main contrib non-free
  80 EOF
  81 # Install non-free binary blob needed to boot Raspberry Pi.  This
  82 # install a kernel somewhere too.
  83 wget https://raw.github.com/Hexxeh/rpi-update/master/rpi-update \
  84     -O $rootdir/usr/bin/rpi-update
  85 chmod a+x $rootdir/usr/bin/rpi-update
  86 mkdir -p $rootdir/lib/modules
  87 touch $rootdir/boot/start.elf
  88 chroot $rootdir rpi-update
  89 </pre></p>
  90
  91 <p>Next, fetch the latest vmdebootstrap script and call it like this
  92 to build the image:</p>
  93
  94 <pre>
  95 sudo ./vmdebootstrap \
  96     --variant minbase \
  97     --arch armel \
  98     --distribution jessie \
  99     --mirror http://http.debian.net/debian \
 100     --image test.img \
 101     --size 600M \
 102     --bootsize 64M \
 103     --boottype vfat \
 104     --log-level debug \
 105     --verbose \
 106     --no-kernel \
 107     --no-extlinux \
 108     --root-password raspberry \
 109     --hostname raspberrypi \
 110     --foreign /usr/bin/qemu-arm-static \
 111     --customize `pwd`/customize \
 112     --package netbase \
 113     --package git-core \
 114     --package binutils \
 115     --package ca-certificates \
 116     --package wget \
 117     --package kmod
 118 </pre></p>
 119
 120 <p>The list of packages being installed are the ones needed by
 121 rpi-update to make the image bootable on the Raspberry Pi, with the
 122 exception of netbase, which is needed by debootstrap to find
 123 /etc/hosts with the minbase variant.  I really wish there was a way to
 124 set up an Raspberry Pi using only packages in the Debian archive, but
 125 that is not possible as far as I know, because it boots from the GPU
 126 using a non-free binary blob.</p>
 127
 128 <p>The build host need debootstrap, kpartx and qemu-user-static and
 129 probably a few others installed.  I have not checked the complete
 130 build dependency list.</p>
 131
 132 <p>The resulting image will not use the hardware floating point unit
 133 on the Raspberry PI, because the armel architecture in Debian is not
 134 optimized for that use.  So the images created will be a bit slower
 135 than <a href="http://www.raspbian.org/">Raspbian</a> based images.</p>
 136
 137       </div>
 138       <div class="tags">
 139
 140
 141         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox</a>, <a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network</a>.
 142
 143
 144       </div>
 145     </div>
 146     <div class="padding"></div>
 147
 148     <div class="entry">
 149       <div class="title">
 150         <a href="http://people.skolelinux.org/pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html">A Raspberry Pi based batman-adv Mesh network node</a>
 151       </div>
 152       <div class="date">
 153         21st October 2013
 154       </div>
 155       <div class="body">
 156         <p>The last few days I have been experimenting with
 157 <a href="http://www.open-mesh.org/projects/batman-adv/wiki">the
 158 batman-adv mesh technology</a>.  I want to gain some experience to see
 159 if it will fit <a href="https://wiki.debian.org/FreedomBox">the
 160 Freedombox project</a>, and together with my neighbors try to build a
 161 mesh network around the park where I live.  Batman-adv is a layer 2
 162 mesh system ("ethernet" in other words), where the mesh network appear
 163 as if all the mesh clients are connected to the same switch.</p>
 164
 165 <p>My hardware of choice was the Linksys WRT54GL routers I had lying
 166 around, but I've been unable to get them working with batman-adv.  So
 167 instead, I started playing with a
 168 <a href="http://www.raspberrypi.org/">Raspberry Pi</a>, and tried to
 169 get it working as a mesh node.  My idea is to use it to create a mesh
 170 node which function as a switch port, where everything connected to
 171 the Raspberry Pi ethernet plug is connected (bridged) to the mesh
 172 network.  This allow me to hook a wifi base station like the Linksys
 173 WRT54GL to the mesh by plugging it into a Raspberry Pi, and allow
 174 non-mesh clients to hook up to the mesh.  This in turn is useful for
 175 Android phones using <a href="http://servalproject.org/">the Serval
 176 Project</a> voip client, allowing every one around the playground to
 177 phone and message each other for free.  The reason is that Android
 178 phones do not see ad-hoc wifi networks (they are filtered away from
 179 the GUI view), and can not join the mesh without being rooted.  But if
 180 they are connected using a normal wifi base station, they can talk to
 181 every client on the local network.</p>
 182
 183 <p>To get this working, I've created a debian package
 184 <a href="https://github.com/petterreinholdtsen/meshfx-node">meshfx-node</a>
 185 and a script
 186 <a href="https://github.com/petterreinholdtsen/meshfx-node/blob/master/build-rpi-mesh-node">build-rpi-mesh-node</a>
 187 to create the Raspberry Pi boot image.  I'm using Debian Jessie (and
 188 not Raspbian), to get more control over the packages available.
 189 Unfortunately a huge binary blob need to be inserted into the boot
 190 image to get it booting, but I'll ignore that for now.  Also, as
 191 Debian lack support for the CPU features available in the Raspberry
 192 Pi, the system do not use the hardware floating point unit.  I hope
 193 the routing performance isn't affected by the lack of hardware FPU
 194 support.</p>
 195
 196 <p>To create an image, run the following with a sudo enabled user
 197 after inserting the target SD card into the build machine:</p>
 198
 199 <p><pre>
 200 % wget -O build-rpi-mesh-node \
 201     https://raw.github.com/petterreinholdtsen/meshfx-node/master/build-rpi-mesh-node
 202 % sudo bash -x ./build-rpi-mesh-node > build.log 2>&1
 203 % dd if=/root/rpi/rpi_basic_jessie_$(date +%Y%m%d).img of=/dev/mmcblk0 bs=1M
 204 %
 205 </pre></p>
 206
 207 <p>Booting with the resulting SD card on a Raspberry PI with a USB
 208 wifi card inserted should give you a mesh node.  At least it does for
 209 me with a the wifi card I am using. The default mesh settings are the
 210 ones used by the Oslo mesh project at Hackeriet, as I mentioned in
 211 <a href="http://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html">an
 212 earlier blog post about this mesh testing</a>.</p>
 213
 214 <p>The mesh node was not horribly expensive either.  I bought
 215 everything over the counter in shops nearby.  If I had ordered online
 216 from the lowest bidder, the price should be significantly lower:</p>
 217
 218 <p><table>
 219
 220 <tr><th>Supplier</th><th>Model</th><th>NOK</th></tr>
 221 <tr><td>Teknikkmagasinet</td><td>Raspberry Pi model B</td><td>349.90</td></tr>
 222 <tr><td>Teknikkmagasinet</td><td>Raspberry Pi type B case</td><td>99.90</td></tr>
 223 <tr><td>Lefdal</td><td>Jensen Air:Link 25150</td><td>295.-</td></tr>
 224 <tr><td>Clas Ohlson</td><td>Kingston 16 GB SD card</td><td>199.-</td></tr>
 225 <tr><td>Total cost</td><td></td><td>943.80</td></tr>
 226
 227 </table></p>
 228
 229 <p>Now my mesh network at home consist of one laptop in the basement
 230 connected to my production network, one Raspberry Pi node on the 1th
 231 floor that can be seen by my neighbor across the park, and one
 232 play-node I use to develop the image building script.  And some times
 233 I hook up my work horse laptop to the mesh to test it.  I look forward
 234 to figuring out what kind of latency the batman-adv setup will give,
 235 and how much packet loss we will experience around the park. :)</p>
 236
 237       </div>
 238       <div class="tags">
 239
 240
 241         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox</a>, <a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
 242
 243
 244       </div>
 245     </div>
 246     <div class="padding"></div>
 247
 248     <div class="entry">
 249       <div class="title">
 250         <a href="http://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html">Oslo community mesh network - with NUUG and Hackeriet at Hausmania</a>
 251       </div>
 252       <div class="date">
 253         11th October 2013
 254       </div>
 255       <div class="body">
 256         <p>Wireless mesh networks are self organising and self healing
 257 networks that can be used to connect computers across small and large
 258 areas, depending on the radio technology used.  Normal wifi equipment
 259 can be used to create home made radio networks, and there are several
 260 successful examples like
 261 <a href="http://www.freifunk.net/">Freifunk</a> and
 262 <a href="http://www.awmn.net/">Athens Wireless Metropolitan Network</a>
 263 (see
 264 <a href="http://en.wikipedia.org/wiki/List_of_wireless_community_networks_by_region#Greece">wikipedia
 265 for a large list</a>) around the globe.  To give you an idea how it
 266 work, check out the nice overview of the Kiel Freifunk community which
 267 can be seen from their
 268 <a href="http://freifunk.in-kiel.de/ffmap/nodes.html">dynamically
 269 updated node graph and map</a>, where one can see how the mesh nodes
 270 automatically handle routing and recover from nodes disappearing.
 271 There is also a small community mesh network group in Oslo, Norway,
 272 and that is the main topic of this blog post.</p>
 273
 274 <p>I've wanted to check out mesh networks for a while now, and hoped
 275 to do it as part of my involvement with the <a
 276 href="http://www.nuug.no/">NUUG member organisation</a> community, and
 277 my recent involvement in
 278 <a href="https://wiki.debian.org/FreedomBox">the Freedombox project</a>
 279 finally lead me to give mesh networks some priority, as I suspect a
 280 Freedombox should use mesh networks to connect neighbours and family
 281 when possible, given that most communication between people are
 282 between those nearby (as shown for example by research on Facebook
 283 communication patterns).  It also allow people to communicate without
 284 any central hub to tap into for those that want to listen in on the
 285 private communication of citizens, which have become more and more
 286 important over the years.</p>
 287
 288 <p>So far I have only been able to find one group of people in Oslo
 289 working on community mesh networks, over at the hack space
 290 <a href="http://hackeriet.no/">Hackeriet</a> at Husmania.  They seem to
 291 have started with some Freifunk based effort using OLSR, called
 292 <a href="http://oslo.freifunk.net/index.php?title=Main_Page">the Oslo
 293 Freifunk project</a>, but that effort is now dead and the people
 294 behind it have moved on to a batman-adv based system called
 295 <a href="http://meshfx.org/trac">meshfx</a>.  Unfortunately the wiki
 296 site for the Oslo Freifunk project is no longer possible to update to
 297 reflect this fact, so the old project page can't be updated to point to
 298 the new project.  A while back, the people at Hackeriet invited people
 299 from the Freifunk community to Oslo to talk about mesh networks.  I
 300 came across this video where Hans Jørgen Lysglimt interview the
 301 speakers about this talk (from
 302 <a href="https://www.youtube.com/watch?v=N2Kd7CLkhSY">youtube</a>):</p>
 303
 304 <p><iframe width="420" height="315" src="https://www.youtube.com/embed/N2Kd7CLkhSY" frameborder="0" allowfullscreen></iframe></p>
 305
 306 <p>I mentioned OLSR and batman-adv, which are mesh routing protocols.
 307 There are heaps of different protocols, and I am still struggling to
 308 figure out which one would be "best" for some definitions of best, but
 309 given that the community mesh group in Oslo is so small, I believe it
 310 is best to hook up with the existing one instead of trying to create a
 311 completely different setup, and thus I have decided to focus on
 312 batman-adv for now.  It sure help me to  know that the very cool
 313 <a href="http://www.servalproject.org/">Serval project in Australia</a>
 314 is using batman-adv as their meshing technology when it create a self
 315 organizing and self healing telephony system for disaster areas and
 316 less industrialized communities.  Check out this cool video presenting
 317 that project (from
 318 <a href="https://www.youtube.com/watch?v=30qNfzJCQOA">youtube</a>):</p>
 319
 320 <p><iframe width="560" height="315" src="https://www.youtube.com/embed/30qNfzJCQOA" frameborder="0" allowfullscreen></iframe></p>
 321
 322 <p>According to the wikipedia page on
 323 <a href="http://en.wikipedia.org/wiki/Wireless_mesh_network">Wireless
 324 mesh network</a> there are around 70 competing schemes for routing
 325 packets across mesh networks, and OLSR, B.A.T.M.A.N. and
 326 B.A.T.M.A.N. advanced are protocols used by several free software
 327 based community mesh networks.</p>
 328
 329 <p>The batman-adv protocol is a bit special, as it provide layer 2
 330 (as in ethernet ) routing, allowing ipv4 and ipv6 to work on the same
 331 network.  One way to think about it is that it provide a mesh based
 332 vlan you can bridge to or handle like any other vlan connected to your
 333 computer.  The required drivers are already in the Linux kernel at
 334 least since Debian Wheezy, and it is fairly easy to set up.  A
 335 <a href="http://www.open-mesh.org/projects/batman-adv/wiki/Quick-start-guide">good
 336 introduction</a> is available from the Open Mesh project.  These are
 337 the key settings needed to join the Oslo meshfx network:</p>
 338
 339 <p><table>
 340 <tr><th>Setting</th><th>Value</th></tr>
 341 <tr><td>Protocol / kernel module</td><td>batman-adv</td></tr>
 342 <tr><td>ESSID</td><td>meshfx@hackeriet</td></tr>
 343 <td>Channel / Frequency</td><td>11 / 2462</td></tr>
 344 <td>Cell ID</td><td>02:BA:00:00:00:01</td>
 345 </table></p>
 346
 347 <p>The reason for setting ad-hoc wifi Cell ID is to work around bugs
 348 in firmware used in wifi card and wifi drivers.  (See a nice post from
 349 VillageTelco about
 350 "<a href="http://tiebing.blogspot.no/2009/12/ad-hoc-cell-splitting-re-post-original.html">Information
 351 about cell-id splitting, stuck beacons, and failed IBSS merges!</a>
 352 for details.)  When these settings are activated and you have some
 353 other mesh node nearby, your computer will be connected to the mesh
 354 network and can communicate with any mesh node that is connected to
 355 any of the nodes in your network of nodes. :)</p>
 356
 357 <p>My initial plan was to reuse my old Linksys WRT54GL as a mesh node,
 358 but that seem to be very hard, as I have not been able to locate a
 359 firmware supporting batman-adv.  If anyone know how to use that old
 360 wifi access point with batman-adv these days, please let me know.</p>
 361
 362 <p>If you find this project interesting and want to join, please join
 363 us on IRC, either channel
 364 <a href="irc://irc.freenode.net/#oslohackerspace">#oslohackerspace</a>
 365 or <a href="irc://irc.freenode.net/#nuug">#nuug</a> on
 366 irc.freenode.net.</p>
 367
 368 <p>While investigating mesh networks in Oslo, I came across an old
 369 research paper from the university of Stavanger and Telenor Research
 370 and Innovation called
 371 <a href="http://folk.uio.no/paalee/publications/netrel-egeland-iswcs-2008.pdf">The
 372 reliability of wireless backhaul mesh networks</a> and elsewhere
 373 learned that Telenor have been experimenting with mesh networks at
 374 Grünerløkka in Oslo.  So mesh networks are also interesting for
 375 commercial companies, even though Telenor discovered that it was hard
 376 to figure out a good business plan for mesh networking and as far as I
 377 know have closed down the experiment.  Perhaps Telenor or others would
 378 be interested in a cooperation?</p>
 379
 380 <p><strong>Update 2013-10-12</strong>: I was just
 381 <a href="http://lists.alioth.debian.org/pipermail/freedombox-discuss/2013-October/005900.html">told
 382 by the Serval project developers</a> that they no longer use
 383 batman-adv (but are compatible with it), but their own crypto based
 384 mesh system.</p>
 385
 386       </div>
 387       <div class="tags">
 388
 389
 390         Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox</a>, <a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
 391
 392
 393       </div>
 394     </div>
 395     <div class="padding"></div>
 396
 397     <p style="text-align: right;"><a href="mesh network.rss"><img src="http://people.skolelinux.org/pere/blog/xml.gif" alt="RSS Feed" width="36" height="14" /></a></p>
 398     <div id="sidebar">
 399
 400
 401
 402 <h2>Archive</h2>
 403 <ul>
 404
 405 <li>2013
 406 <ul>
 407
 408 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/01/">January (11)</a></li>
 409
 410 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/02/">February (9)</a></li>
 411
 412 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/03/">March (9)</a></li>
 413
 414 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/04/">April (6)</a></li>
 415
 416 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/05/">May (9)</a></li>
 417
 418 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/06/">June (10)</a></li>
 419
 420 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/07/">July (7)</a></li>
 421
 422 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/08/">August (3)</a></li>
 423
 424 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/09/">September (5)</a></li>
 425
 426 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/10/">October (7)</a></li>
 427
 428 </ul></li>
 429
 430 <li>2012
 431 <ul>
 432
 433 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/01/">January (7)</a></li>
 434
 435 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/02/">February (10)</a></li>
 436
 437 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/03/">March (17)</a></li>
 438
 439 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/04/">April (12)</a></li>
 440
 441 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/05/">May (12)</a></li>
 442
 443 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/06/">June (20)</a></li>
 444
 445 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/07/">July (17)</a></li>
 446
 447 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/08/">August (6)</a></li>
 448
 449 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/09/">September (9)</a></li>
 450
 451 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/10/">October (17)</a></li>
 452
 453 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/11/">November (10)</a></li>
 454
 455 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/12/">December (7)</a></li>
 456
 457 </ul></li>
 458
 459 <li>2011
 460 <ul>
 461
 462 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/01/">January (16)</a></li>
 463
 464 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/02/">February (6)</a></li>
 465
 466 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/03/">March (6)</a></li>
 467
 468 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/04/">April (7)</a></li>
 469
 470 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/05/">May (3)</a></li>
 471
 472 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/06/">June (2)</a></li>
 473
 474 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/07/">July (7)</a></li>
 475
 476 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/08/">August (6)</a></li>
 477
 478 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/09/">September (4)</a></li>
 479
 480 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/10/">October (2)</a></li>
 481
 482 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/11/">November (3)</a></li>
 483
 484 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/12/">December (1)</a></li>
 485
 486 </ul></li>
 487
 488 <li>2010
 489 <ul>
 490
 491 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/01/">January (2)</a></li>
 492
 493 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/02/">February (1)</a></li>
 494
 495 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/03/">March (3)</a></li>
 496
 497 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/04/">April (3)</a></li>
 498
 499 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/05/">May (9)</a></li>
 500
 501 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/06/">June (14)</a></li>
 502
 503 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/07/">July (12)</a></li>
 504
 505 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/08/">August (13)</a></li>
 506
 507 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/09/">September (7)</a></li>
 508
 509 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/10/">October (9)</a></li>
 510
 511 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/11/">November (13)</a></li>
 512
 513 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/12/">December (12)</a></li>
 514
 515 </ul></li>
 516
 517 <li>2009
 518 <ul>
 519
 520 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/01/">January (8)</a></li>
 521
 522 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/02/">February (8)</a></li>
 523
 524 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/03/">March (12)</a></li>
 525
 526 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/04/">April (10)</a></li>
 527
 528 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/05/">May (9)</a></li>
 529
 530 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/06/">June (3)</a></li>
 531
 532 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/07/">July (4)</a></li>
 533
 534 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/08/">August (3)</a></li>
 535
 536 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/09/">September (1)</a></li>
 537
 538 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/10/">October (2)</a></li>
 539
 540 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/11/">November (3)</a></li>
 541
 542 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/12/">December (3)</a></li>
 543
 544 </ul></li>
 545
 546 <li>2008
 547 <ul>
 548
 549 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/11/">November (5)</a></li>
 550
 551 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/12/">December (7)</a></li>
 552
 553 </ul></li>
 554
 555 </ul>
 556
 557
 558
 559 <h2>Tags</h2>
 560 <ul>
 561
 562  <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (13)</a></li>
 563
 564  <li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
 565
 566  <li><a href="http://people.skolelinux.org/pere/blog/tags/aros">aros (1)</a></li>
 567
 568  <li><a href="http://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
 569
 570  <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (7)</a></li>
 571
 572  <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (12)</a></li>
 573
 574  <li><a href="http://people.skolelinux.org/pere/blog/tags/bsa">bsa (2)</a></li>
 575
 576  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (88)</a></li>
 577
 578  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (142)</a></li>
 579
 580  <li><a href="http://people.skolelinux.org/pere/blog/tags/digistan">digistan (10)</a></li>
 581
 582  <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (10)</a></li>
 583
 584  <li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
 585
 586  <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (223)</a></li>
 587
 588  <li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (21)</a></li>
 589
 590  <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (12)</a></li>
 591
 592  <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (12)</a></li>
 593
 594  <li><a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (5)</a></li>
 595
 596  <li><a href="http://people.skolelinux.org/pere/blog/tags/frikanalen">frikanalen (11)</a></li>
 597
 598  <li><a href="http://people.skolelinux.org/pere/blog/tags/intervju">intervju (37)</a></li>
 599
 600  <li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (7)</a></li>
 601
 602  <li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (18)</a></li>
 603
 604  <li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (8)</a></li>
 605
 606  <li><a href="http://people.skolelinux.org/pere/blog/tags/lenker">lenker (6)</a></li>
 607
 608  <li><a href="http://people.skolelinux.org/pere/blog/tags/ltsp">ltsp (1)</a></li>
 609
 610  <li><a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network (3)</a></li>
 611
 612  <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (25)</a></li>
 613
 614  <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (236)</a></li>
 615
 616  <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (156)</a></li>
 617
 618  <li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (8)</a></li>
 619
 620  <li><a href="http://people.skolelinux.org/pere/blog/tags/open311">open311 (2)</a></li>
 621
 622  <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (45)</a></li>
 623
 624  <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (67)</a></li>
 625
 626  <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (1)</a></li>
 627
 628  <li><a href="http://people.skolelinux.org/pere/blog/tags/reprap">reprap (11)</a></li>
 629
 630  <li><a href="http://people.skolelinux.org/pere/blog/tags/rfid">rfid (2)</a></li>
 631
 632  <li><a href="http://people.skolelinux.org/pere/blog/tags/robot">robot (8)</a></li>
 633
 634  <li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
 635
 636  <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (4)</a></li>
 637
 638  <li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
 639
 640  <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (32)</a></li>
 641
 642  <li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>
 643
 644  <li><a href="http://people.skolelinux.org/pere/blog/tags/skepsis">skepsis (4)</a></li>
 645
 646  <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (43)</a></li>
 647
 648  <li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (3)</a></li>
 649
 650  <li><a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (9)</a></li>
 651
 652  <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (20)</a></li>
 653
 654  <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (1)</a></li>
 655
 656  <li><a href="http://people.skolelinux.org/pere/blog/tags/valg">valg (8)</a></li>
 657
 658  <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (39)</a></li>
 659
 660  <li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (4)</a></li>
 661
 662  <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (28)</a></li>
 663
 664 </ul>
 665
 666
 667     </div>
 668     <p style="text-align: right">
 669  Created by <a href="http://steve.org.uk/Software/chronicle">Chronicle v4.6</a>
 670 </p>
 671
 672   </body>
 673 </html>