blog/tags/mesh network/index.html

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