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5 <title>Petter Reinholdtsen</title>
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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
22 <div class="entry">
23 <div class="title"><a href="http://people.skolelinux.org/pere/blog/Autodetecting_Client_setup_for_roaming_workstations_in_Debian_Edu.html">Autodetecting Client setup for roaming workstations in Debian Edu</a></div>
24 <div class="date">2010-08-07 14:45</div>
25 <div class="body">
26 <p>A few days ago, I
27 <a href="http://people.skolelinux.org/pere/blog/Debian_Edu_roaming_workstation___at_the_university_of_Oslo.html">tried
28 to install</a> a Roaming workation profile from Debian Edu/Squeeze
29 while on the university network here at the University of Oslo, and
30 noticed how much had to change to get it operational using the
31 university infrastructure. It was fairly easy, but it occured to me
32 that Debian Edu would improve a lot if I could get the client to
33 connect without any changes at all, and thus let the client configure
34 itself during installation and first boot to use the infrastructure
35 around it. Now I am a huge step further along that road.</p>
36
37 <p>With our current squeeze-test packages, I can select the roaming
38 workstation profile and get a working laptop connecting to the
39 university LDAP server for user and group and our active directory
40 servers for Kerberos authentication. All this without any
41 configuration at all during installation. My users home directory got
42 a bookmark in the KDE menu to mount it via SMB, with the correct URL.
43 In short, openldap and sssd is correctly configured. In addition to
44 this, the client look for http://wpad/wpad.dat to configure a web
45 proxy, and when it fail to find it no proxy settings are stored in
46 /etc/environment and /etc/apt/apt.conf. Iceweasel and KDE is
47 configured to look for the same wpad configuration and also do not use
48 a proxy when at the university network. If the machine is moved to a
49 network with such wpad setup, it would automatically use it when DHCP
50 gave it a IP address.</p>
51
52 <p>The LDAP server is located using DNS, by first looking for the DNS
53 entry ldap.$domain. If this do not exist, it look for the
54 _ldap._tcp.$domain SRV records and use the first one as the LDAP
55 server. Next, it connects to the LDAP server and search all
56 namingContexts entries for posixAccount or posixGroup objects, and
57 pick the first one as the LDAP base. For Kerberos, a similar
58 algorithm is used to locate the LDAP server, and the realm is the
59 uppercase version of $domain.</p>
60
61 <p>So, what is not working, you might ask. SMB mounting my home
62 directory do not work. No idea why, but suspected the incorrect
63 Kerberos settings in /etc/krb5.conf and /etc/samba/smb.conf might be
64 the cause. These are not properly configured during installation, and
65 had to be hand-edited to get the correct Kerberos realm and server,
66 but SMB mounting still do not work. :(</p>
67
68 <p>With this automatic configuration in place, I expect a Debian Edu
69 roaming profile installation would be able to automatically detect and
70 connect to any site using LDAP and Kerberos for NSS directory and PAM
71 authentication. It should also work out of the box in a Active
72 Directory environment providing posixAccount and posixGroup objects
73 with UID and GID values.</p>
74
75 <p>If you want to help out with implementing these things for Debian
76 Edu, please contact us on debian-edu@lists.debian.org.</p>
77 </div>
78 <div class="tags">
79
80
81
82 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
83
84 </div>
85 </div>
86 <div class="padding"></div>
87
88 <div class="entry">
89 <div class="title"><a href="http://people.skolelinux.org/pere/blog/Debian_Edu_roaming_workstation___at_the_university_of_Oslo.html">Debian Edu roaming workstation - at the university of Oslo</a></div>
90 <div class="date">2010-08-03 23:30</div>
91 <div class="body">
92 <p>The new roaming workstation profile in Debian Edu/Squeeze is fairly
93 similar to the laptop setup am I working on using Ubuntu for the
94 University of Oslo, and just for the heck of it, I tested today how
95 hard it would be to integrate that profile into the university
96 infrastructure. In this case, it is the university LDAP server,
97 Active Directory Kerberos server and SMB mounting from the Netapp file
98 servers.</p>
99
100 <p>I was pleasantly surprised that the only three files needed to be
101 changed (/etc/sssd/sssd.conf, /etc/ldap.conf and
102 /etc/mklocaluser.d/20-debian-edu-config) and one file had to be added
103 (/usr/share/perl5/Debian/Edu_Local.pm), to get the client working.
104 Most of the changes were to get the client to use the university LDAP
105 for NSS and Kerberos server for PAM, but one was to change a hard
106 coded DNS domain name in the mklocaluser hook from .intern to
107 .uio.no.</p>
108
109 <p>This testing was so encouraging, that I went ahead and adjusted the
110 Debian Edu scripts and setup in subversion to centralise the roaming
111 workstation setup a bit more and avoid the hardcoded DNS domain name,
112 so that when I test this tomorrow, I expect to get away with modifying
113 only /etc/sssd/sssd.conf and /etc/ldap.conf to get it to use the
114 university servers.</p>
115
116 <p>My goal is to get the clients to have no hardcoded settings and
117 fetch all their initial setup during installation and first boot, to
118 allow them to be inserted also into environments where the default
119 setup in Debian Edu has been changed or as with the university, where
120 the environment is different but provides the protocols Debian Edu
121 uses.</p>
122 </div>
123 <div class="tags">
124
125
126
127 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
128
129 </div>
130 </div>
131 <div class="padding"></div>
132
133 <div class="entry">
134 <div class="title"><a href="http://people.skolelinux.org/pere/blog/Circular_package_dependencies_harms_apt_recovery.html">Circular package dependencies harms apt recovery</a></div>
135 <div class="date">2010-07-27 23:50</div>
136 <div class="body">
137 <p>I discovered this while doing
138 <a href="http://people.skolelinux.org/pere/blog/Automatic_upgrade_testing_from_Lenny_to_Squeeze.html">automated
139 testing of upgrades from Debian Lenny to Squeeze</a>. A few packages
140 in Debian still got circular dependencies, and it is often claimed
141 that apt and aptitude should be able to handle this just fine, but
142 some times these dependency loops causes apt to fail.</p>
143
144 <p>An example is from todays
145 <a href="http://people.skolelinux.org/~pere/debian-upgrade-testing//test-20100727-lenny-squeeze-kde-aptitude.txt">upgrade
146 of KDE using aptitude</a>. In it, a bug in kdebase-workspace-data
147 causes perl-modules to fail to upgrade. The cause is simple. If a
148 package fail to unpack, then only part of packages with the circular
149 dependency might end up being unpacked when unpacking aborts, and the
150 ones already unpacked will fail to configure in the recovery phase
151 because its dependencies are unavailable.</p>
152
153 <p>In this log, the problem manifest itself with this error:</p>
154
155 <blockquote><pre>
156 dpkg: dependency problems prevent configuration of perl-modules:
157 perl-modules depends on perl (>= 5.10.1-1); however:
158 Version of perl on system is 5.10.0-19lenny2.
159 dpkg: error processing perl-modules (--configure):
160 dependency problems - leaving unconfigured
161 </pre></blockquote>
162
163 <p>The perl/perl-modules circular dependency is already
164 <a href="http://bugs.debian.org/527917">reported as a bug</a>, and will
165 hopefully be solved as soon as possible, but it is not the only one,
166 and each one of these loops in the dependency tree can cause similar
167 failures. Of course, they only occur when there are bugs in other
168 packages causing the unpacking to fail, but it is rather nasty when
169 the failure of one package causes the problem to become worse because
170 of dependency loops.</p>
171
172 <p>Thanks to
173 <a href="http://lists.debian.org/debian-devel/2010/06/msg00116.html">the
174 tireless effort by Bill Allombert</a>, the number of circular
175 dependencies
176 <a href="http://debian.semistable.com/debgraph.out.html">left in Debian
177 is dropping</a>, and perhaps it will reach zero one day. :)</p>
178
179 <p>Todays testing also exposed a bug in
180 <a href="http://bugs.debian.org/590605">update-notifier</a> and
181 <a href="http://bugs.debian.org/590604">different behaviour</a> between
182 apt-get and aptitude, the latter possibly caused by some circular
183 dependency. Reported both to BTS to try to get someone to look at
184 it.</p>
185 </div>
186 <div class="tags">
187
188
189
190 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/nuug">nuug</a>.
191
192 </div>
193 </div>
194 <div class="padding"></div>
195
196 <div class="entry">
197 <div class="title"><a href="http://people.skolelinux.org/pere/blog/First_Debian_Edu_test_release__alpha0__based_on_Squeeze_is_released.html">First Debian Edu test release (alpha0) based on Squeeze is released</a></div>
198 <div class="date">2010-07-27 17:45</div>
199 <div class="body">
200 <p>I just posted this announcement culminating several months of work
201 with the next Debian Edu release. Not nearly done, but one major step
202 completed.</p>
203
204 <blockquote>
205 <p>This is the first test release based on Squeeze. The focus of this
206 release is to test the user application selection. To have a look,
207 install the standalone profile and let the developers know if the set
208 of installed packages i.e. applications should be modified. If some
209 user application is missing, or if there are some applications that no
210 longer make sense to be included in Debian Edu, please let us know.
211 Also, if a useful application is missing the translation for your
212 language of choice, please let us know too.</p>
213
214 <p>In addition, feedback and help to polish the desktop (menus,
215 artwork, starters, etc.) is appreciated. We would like to ship a nice
216 and handy KDE4 desktop targeted for schools out of the box.</p>
217
218 <p>The other profiles should be installable, but there is a lot more
219 work left to be done before they are ready, so do not expect to
220 much.</p>
221
222 <p>Changes compared to the lenny based version</p>
223
224 <ul>
225 <li>Everything from Debian Squeeze
226 <ul>
227 <li>Desktop environment KDE 4.4 => the new KDE desktop in
228 combination with some new artwork
229 <li>Web browser Iceweasel 3.5
230 <li>OpenOffice.org 3.2
231 <li>Educational toolbox GCompris 9.3
232 <li>Music creator Rosegarden 10.04.2
233 <li>Image editor Gimp 2.6.10
234 <li>Virtual universe Celestia 1.6.0
235 <li>Virtual stargazer Stellarium 0.10.4
236 <li>3D modeler Blender 2.49.2 (new application)
237 <li>Video editor Kdenlive 0.7.7 (new application)
238 </ul></li>
239 <li>Now using Kerberos for password checking (migration not finished).
240 Enabled for:
241 <ul>
242 <li>PAM
243 <li>LDAP
244 <li>IMAP
245 <li>SMTP (sender verification)
246 </ul>
247 </li>
248 <li>New experimental roaming workstation profile for laptops.</li>
249 <li>Show welcome page to users when they first log in. The URL is
250 fetched from LDAP.</li>
251 <li>New LXDE desktop option, in addition to KDE (default) and Gnome.</li>
252 <li>General cleanup (not finished)</li>
253 </ul>
254 <p>The following features are not working as they should</p>
255
256 <ul>
257 <li>No web based administration tool for creating users and groups. The
258 scripts ldap-createuser-krb and ldap-add-user-to-group can be used
259 for testing.</li>
260 <li>DVD installs are missing debian-installer images for the PXE boot,
261 and do not set up the PXE menu on eth0 because of this. LTSP
262 clients should still boot from eth1 on thin client servers.</li>
263 <li>The restructured KDE menu is not implemented.</li>
264 <li>The LDAP server setup need to be reviewed for security.</li>
265 <li>The LDAP directory structure need to be reworked.</li>
266 <li>Different sets of packages are installed when using the DVD and the
267 netinst CD. More packages are installed using the netinst CD.</li>
268 <li>The jackd package fail to install. This is believed to be caused by
269 some ongoing transition, and hopefully should be solved soon. The
270 jackd1 package can be installed manually for those that need it.</li>
271 <li>Some packages lack translations. See
272 http://wiki.debian.org/DebianEdu/Status/Squeeze for updated status,
273 and help out with translations.</li>
274 </ul>
275
276 <p>To download this multiarch netinstall release you can use</p>
277
278 <ul>
279 <li><a href="ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-CD.iso">ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-CD.iso</a></li>
280 <li><a href="http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-CD.iso">http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-CD.iso</a></li>
281 <li>rsync -avzP ftp.skolelinux.org::skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-CD.iso</li>
282 </ul>
283 <p>To download this multiarch dvd release you can use</p>
284
285 <ul>
286 <li><a href="ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-DVD.iso">ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-DVD.iso</a></li>
287 <li><a href="http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-DVD.iso">http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-DVD.iso</a></li>
288 <li>rsync -avzP ftp.skolelinux.org::skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-DVD.iso</li>
289 </ul>
290
291 <p>There is no source DVD available yet. It will be prepared when we
292 get closer to the final release.</p>
293
294 <p>The MD5SUM of these images are</p>
295
296 <ul>
297 <li>3dbf45d59f42a53518b6e3c9ec3b5eb6 debian-edu-6.0.0+edua0-CD.iso</li>
298 <li>22f2cbfce281d1c6e478be452638675d debian-edu-6.0.0+edua0-DVD.iso</li>
299 </ul>
300
301 <p>The SHA1SUM of these images are</p>
302 <ul>
303 <li>c53d1b69b40cf37cd27aefaf33f6f6a3821bedf0 debian-edu-6.0.0+edua0-CD.iso</li>
304 <li>2ec29d7db676d59d32197b05c277ffe16348376c debian-edu-6.0.0+edua0-DVD.iso</li>
305 </ul>
306 <p>How to report bugs:
307 http://wiki.debian.org/DebianEdu/HowTo/ReportBugsInBugzilla</p>
308
309 <p>Please direct replies to debian-edu@lists.debian.org</p>
310 </blockquote>
311 </div>
312 <div class="tags">
313
314
315
316 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
317
318 </div>
319 </div>
320 <div class="padding"></div>
321
322 <div class="entry">
323 <div class="title"><a href="http://people.skolelinux.org/pere/blog/One_step_closer_to_single_signon_in_Debian_Edu.html">One step closer to single signon in Debian Edu</a></div>
324 <div class="date">2010-07-25 10:00</div>
325 <div class="body">
326 <p>The last few months me and the other Debian Edu developers have
327 been working hard to get the Debian/Squeeze based version of Debian
328 Edu/Skolelinux into shape. This future version will use Kerberos for
329 authentication, and services are slowly migrated to single signon,
330 getting rid of password questions one at the time.</p>
331
332 <p>It will also feature a roaming workstation profile with local home
333 directory, for laptops that are only some times on the Skolelinux
334 network, and for this profile a shortcut is created in Gnome and KDE
335 to gain access to the users home directory on the file server. This
336 shortcut uses SMB at the moment, and yesterday I had time to test if
337 SMB mounting had started working in KDE after we added the cifs-utils
338 package. I was pleasantly surprised how well it worked.</p>
339
340 <p>Thanks to the recent changes to our samba configuration to get it
341 to use Kerberos for authentication, there were no question about user
342 password when mounting the SMB volume. A simple click on the shortcut
343 in the KDE menu, and a window with the home directory popped
344 up. :)</p>
345
346 <p>One step closer to a single signon solution out of the box in
347 Debian Edu. We already had PAM, LDAP, IMAP and SMTP in place, and now
348 also Samba. Next step is Cups and hopefully also NFS.</p>
349
350 <p>We had planned a alpha0 release of Debian Edu for today, but thanks
351 to the autobuilder administrators for some architectures being slow to
352 sign packages, we are still missing the fixed LTSP package we need for
353 the release. It was uploaded three days ago with urgency=high, and if
354 it had entered testing yesterday we would have been able to test it in
355 time for a alpha0 release today. As the binaries for ia64 and powerpc
356 still not uploaded to the Debian archive, we need to delay the alpha
357 release another day.</p>
358
359 <p>If you want to help out with implementing Kerberos for Debian Edu,
360 please contact us on debian-edu@lists.debian.org.</p>
361 </div>
362 <div class="tags">
363
364
365
366 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
367
368 </div>
369 </div>
370 <div class="padding"></div>
371
372 <div class="entry">
373 <div class="title"><a href="http://people.skolelinux.org/pere/blog/Digitale_restriksjonsmekanismer_fikk_meg_til____slutte____kj__pe_musikk.html">Digitale restriksjonsmekanismer fikk meg til å slutte å kjøpe musikk</a></div>
374 <div class="date">2010-07-22 23:50</div>
375 <div class="body">
376 <p>For mange år siden slutte jeg å kjøpe musikk-CDer. Årsaken var at
377 musikkbransjen var godt i gang med å selge platene sine med DRM som
378 gjorde at jeg ikke fikk spilt av musikken jeg kjøpte på utstyret jeg
379 hadde tilgjengelig, dvs. min datamaskin. Det var umulig å se på en
380 plate om den var ødelagt eller ikke, og jeg hadde jo allerede en
381 anseelig samling med plater, så jeg bestemme meg for å slutte å gi
382 penger til en bransje som åpenbart ikke respekterte meg.</p>
383
384 <p>Jeg har mange titalls dager med musikk på CD i dag. Det meste er
385 lagt i et stort arkiv som kan spilles av fra husets datamaskiner (har
386 ikke rukket rippe alt). Jeg ser dermed ikke behovet for å skaffe mer
387 musikk. De fleste av mine favoritter er i hus, og jeg er dermed godt
388 fornøyd.</p>
389
390 <p>Hvis musikkbransjen ønsker mine penger, så må de demonstrere at de
391 setter pris på meg som kunde, og ikke skremme meg bort med DRM og
392 antydninger om at kundene er kriminelle.</p>
393
394 <p>Filmbransjen er like ille, men mens musikk gjerne varer lenge, er
395 filmer mer ferskvare. Har dermed ikke helt sluttet å kjøpe filmer, men
396 holder meg til DVD-filmer som kan spilles av på mine Linuxbokser.
397 Kommer neppe til å ta i bruk Blueray, og ei heller de nye DRM-greiene
398 «Ultraviolet» som be annonsert her om dagen.</p>
399 </div>
400 <div class="tags">
401
402
403
404 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling</a>, <a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett</a>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>.
405
406 </div>
407 </div>
408 <div class="padding"></div>
409
410 <div class="entry">
411 <div class="title"><a href="http://people.skolelinux.org/pere/blog/OpenStreetmap_one_step_closer_to_having_routing_on_its_front_page.html">OpenStreetmap one step closer to having routing on its front page</a></div>
412 <div class="date">2010-07-18 16:45</div>
413 <div class="body">
414 <p>Thanks to
415 <a href="http://feedproxy.google.com/~r/Opengeodata/~3/wUTCzDZk3lc/project-of-the-week-which-way-home">todays
416 opengeodata blog entry</a>, I just discovered that the
417 OpenStreetmap.org site have gotten
418 <a href="http://nroets.dev.openstreetmap.org/demo/index.html?layers=B000FTFTT">support
419 for calculating routes</a>. The support is still experimental and
420 only available from the development server, until more experience is
421 gathered on the user interface and any scalability issues.</p>
422
423 <p>Earlier, the routing I knew about using the OpenStreetmap.org data
424 was provided by <a href="http://maps.cloudmade.com/">Cloudmade</a>,
425 but having it on the main page is required to make everyone aware of
426 the issue. I've had people reject Openstreetmap.org as a viable
427 alternative for them because the front page lacked routing support,
428 and I hope their needs will be catered for when routing show up on the
429 www.openstreetmap.org front page.</p>
430 </div>
431 <div class="tags">
432
433
434
435 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/kart">kart</a>, <a href="http://people.skolelinux.org/pere/blog/tags/web">web</a>.
436
437 </div>
438 </div>
439 <div class="padding"></div>
440
441 <div class="entry">
442 <div class="title"><a href="http://people.skolelinux.org/pere/blog/What_are_they_searching_for___PowerDNS_and_ISC_DHCP_in_LDAP.html">What are they searching for - PowerDNS and ISC DHCP in LDAP</a></div>
443 <div class="date">2010-07-17 21:00</div>
444 <div class="body">
445 <p>This is a
446 <a href="http://people.skolelinux.org/pere/blog/Time_for_new__LDAP_schemas_replacing_RFC_2307_.html">followup</a>
447 on my
448 <a href="http://people.skolelinux.org/pere/blog/Idea_for_a_change_to_LDAP_schemas_allowing_DNS_and_DHCP_info_to_be_combined_into_one_object.html">previous
449 work</a> on
450 <a href="http://people.skolelinux.org/pere/blog/Combining_PowerDNS_and_ISC_DHCP_LDAP_objects.html">merging
451 all</a> the computer related LDAP objects in Debian Edu.</p>
452
453 <p>As a step to try to see if it possible to merge the DNS and DHCP
454 LDAP objects, I have had a look at how the packages pdns-backend-ldap
455 and dhcp3-server-ldap in Debian use the LDAP server. The two
456 implementations are quite different in how they use LDAP.</p>
457
458 To get this information, I started slapd with debugging enabled and
459 dumped the debug output to a file to get the LDAP searches performed
460 on a Debian Edu main-server. Here is a summary.
461
462 <p><strong>powerdns</strong></p>
463
464 <a href="http://www.linuxnetworks.de/doc/index.php/PowerDNS_LDAP_Backend">Clues
465 on how to</a> set up PowerDNS to use a LDAP backend is available on
466 the web.
467
468 <p>PowerDNS have two modes of operation using LDAP as its backend.
469 One "strict" mode where the forward and reverse DNS lookups are done
470 using the same LDAP objects, and a "tree" mode where the forward and
471 reverse entries are in two different subtrees in LDAP with a structure
472 based on the DNS names, as in tjener.intern and
473 2.2.0.10.in-addr.arpa.</p>
474
475 <p>In tree mode, the server is set up to use a LDAP subtree as its
476 base, and uses a "base" scoped search for the DNS name by adding
477 "dc=tjener,dc=intern," to the base with a filter for
478 "(associateddomain=tjener.intern)" for the forward entry and
479 "dc=2,dc=2,dc=0,dc=10,dc=in-addr,dc=arpa," with a filter for
480 "(associateddomain=2.2.0.10.in-addr.arpa)" for the reverse entry. For
481 forward entries, it is looking for attributes named dnsttl, arecord,
482 nsrecord, cnamerecord, soarecord, ptrrecord, hinforecord, mxrecord,
483 txtrecord, rprecord, afsdbrecord, keyrecord, aaaarecord, locrecord,
484 srvrecord, naptrrecord, kxrecord, certrecord, dsrecord, sshfprecord,
485 ipseckeyrecord, rrsigrecord, nsecrecord, dnskeyrecord, dhcidrecord,
486 spfrecord and modifytimestamp. For reverse entries it is looking for
487 the attributes dnsttl, arecord, nsrecord, cnamerecord, soarecord,
488 ptrrecord, hinforecord, mxrecord, txtrecord, rprecord, aaaarecord,
489 locrecord, srvrecord, naptrrecord and modifytimestamp. The equivalent
490 ldapsearch commands could look like this:</p>
491
492 <blockquote><pre>
493 ldapsearch -h ldap \
494 -b dc=tjener,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no \
495 -s base -x '(associateddomain=tjener.intern)' dNSTTL aRecord nSRecord \
496 cNAMERecord sOARecord pTRRecord hInfoRecord mXRecord tXTRecord \
497 rPRecord aFSDBRecord KeyRecord aAAARecord lOCRecord sRVRecord \
498 nAPTRRecord kXRecord certRecord dSRecord sSHFPRecord iPSecKeyRecord \
499 rRSIGRecord nSECRecord dNSKeyRecord dHCIDRecord sPFRecord modifyTimestamp
500
501 ldapsearch -h ldap \
502 -b dc=2,dc=2,dc=0,dc=10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no \
503 -s base -x '(associateddomain=2.2.0.10.in-addr.arpa)'
504 dnsttl, arecord, nsrecord, cnamerecord soarecord ptrrecord \
505 hinforecord mxrecord txtrecord rprecord aaaarecord locrecord \
506 srvrecord naptrrecord modifytimestamp
507 </pre></blockquote>
508
509 <p>In Debian Edu/Lenny, the PowerDNS tree mode is used with
510 ou=hosts,dc=skole,dc=skolelinux,dc=no as the base, and these are two
511 example LDAP objects used there. In addition to these objects, the
512 parent objects all th way up to ou=hosts,dc=skole,dc=skolelinux,dc=no
513 also exist.</p>
514
515 <blockquote><pre>
516 dn: dc=tjener,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no
517 objectclass: top
518 objectclass: dnsdomain
519 objectclass: domainrelatedobject
520 dc: tjener
521 arecord: 10.0.2.2
522 associateddomain: tjener.intern
523
524 dn: dc=2,dc=2,dc=0,dc=10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no
525 objectclass: top
526 objectclass: dnsdomain2
527 objectclass: domainrelatedobject
528 dc: 2
529 ptrrecord: tjener.intern
530 associateddomain: 2.2.0.10.in-addr.arpa
531 </pre></blockquote>
532
533 <p>In strict mode, the server behaves differently. When looking for
534 forward DNS entries, it is doing a "subtree" scoped search with the
535 same base as in the tree mode for a object with filter
536 "(associateddomain=tjener.intern)" and requests the attributes dnsttl,
537 arecord, nsrecord, cnamerecord, soarecord, ptrrecord, hinforecord,
538 mxrecord, txtrecord, rprecord, aaaarecord, locrecord, srvrecord,
539 naptrrecord and modifytimestamp. For reverse entires it also do a
540 subtree scoped search but this time the filter is "(arecord=10.0.2.2)"
541 and the requested attributes are associateddomain, dnsttl and
542 modifytimestamp. In short, in strict mode the objects with ptrrecord
543 go away, and the arecord attribute in the forward object is used
544 instead.</p>
545
546 <p>The forward and reverse searches can be simulated using ldapsearch
547 like this:</p>
548
549 <blockquote><pre>
550 ldapsearch -h ldap -b ou=hosts,dc=skole,dc=skolelinux,dc=no -s sub -x \
551 '(associateddomain=tjener.intern)' dNSTTL aRecord nSRecord \
552 cNAMERecord sOARecord pTRRecord hInfoRecord mXRecord tXTRecord \
553 rPRecord aFSDBRecord KeyRecord aAAARecord lOCRecord sRVRecord \
554 nAPTRRecord kXRecord certRecord dSRecord sSHFPRecord iPSecKeyRecord \
555 rRSIGRecord nSECRecord dNSKeyRecord dHCIDRecord sPFRecord modifyTimestamp
556
557 ldapsearch -h ldap -b ou=hosts,dc=skole,dc=skolelinux,dc=no -s sub -x \
558 '(arecord=10.0.2.2)' associateddomain dnsttl modifytimestamp
559 </pre></blockquote>
560
561 <p>In addition to the forward and reverse searches , there is also a
562 search for SOA records, which behave similar to the forward and
563 reverse lookups.</p>
564
565 <p>A thing to note with the PowerDNS behaviour is that it do not
566 specify any objectclass names, and instead look for the attributes it
567 need to generate a DNS reply. This make it able to work with any
568 objectclass that provide the needed attributes.</p>
569
570 <p>The attributes are normally provided in the cosine (RFC 1274) and
571 dnsdomain2 schemas. The latter is used for reverse entries like
572 ptrrecord and recent DNS additions like aaaarecord and srvrecord.</p>
573
574 <p>In Debian Edu, we have created DNS objects using the object classes
575 dcobject (for dc), dnsdomain or dnsdomain2 (structural, for the DNS
576 attributes) and domainrelatedobject (for associatedDomain). The use
577 of structural object classes make it impossible to combine these
578 classes with the object classes used by DHCP.</p>
579
580 <p>There are other schemas that could be used too, for example the
581 dnszone structural object class used by Gosa and bind-sdb for the DNS
582 attributes combined with the domainrelatedobject object class, but in
583 this case some unused attributes would have to be included as well
584 (zonename and relativedomainname).</p>
585
586 <p>My proposal for Debian Edu would be to switch PowerDNS to strict
587 mode and not use any of the existing objectclasses (dnsdomain,
588 dnsdomain2 and dnszone) when one want to combine the DNS information
589 with DHCP information, and instead create a auxiliary object class
590 defined something like this (using the attributes defined for
591 dnsdomain and dnsdomain2 or dnszone):</p>
592
593 <blockquote><pre>
594 objectclass ( some-oid NAME 'dnsDomainAux'
595 SUP top
596 AUXILIARY
597 MAY ( ARecord $ MDRecord $ MXRecord $ NSRecord $ SOARecord $ CNAMERecord $
598 DNSTTL $ DNSClass $ PTRRecord $ HINFORecord $ MINFORecord $
599 TXTRecord $ SIGRecord $ KEYRecord $ AAAARecord $ LOCRecord $
600 NXTRecord $ SRVRecord $ NAPTRRecord $ KXRecord $ CERTRecord $
601 A6Record $ DNAMERecord
602 ))
603 </pre></blockquote>
604
605 <p>This will allow any object to become a DNS entry when combined with
606 the domainrelatedobject object class, and allow any entity to include
607 all the attributes PowerDNS wants. I've sent an email to the PowerDNS
608 developers asking for their view on this schema and if they are
609 interested in providing such schema with PowerDNS, and I hope my
610 message will be accepted into their mailing list soon.</p>
611
612 <p><strong>ISC dhcp</strong></p>
613
614 <p>The DHCP server searches for specific objectclass and requests all
615 the object attributes, and then uses the attributes it want. This
616 make it harder to figure out exactly what attributes are used, but
617 thanks to the working example in Debian Edu I can at least get an idea
618 what is needed without having to read the source code.</p>
619
620 <p>In the DHCP server configuration, the LDAP base to use and the
621 search filter to use to locate the correct dhcpServer entity is
622 stored. These are the relevant entries from
623 /etc/dhcp3/dhcpd.conf:</p>
624
625 <blockquote><pre>
626 ldap-base-dn "dc=skole,dc=skolelinux,dc=no";
627 ldap-dhcp-server-cn "dhcp";
628 </pre></blockquote>
629
630 <p>The DHCP server uses this information to nest all the DHCP
631 configuration it need. The cn "dhcp" is located using the given LDAP
632 base and the filter "(&(objectClass=dhcpServer)(cn=dhcp))". The
633 search result is this entry:</p>
634
635 <blockquote><pre>
636 dn: cn=dhcp,dc=skole,dc=skolelinux,dc=no
637 cn: dhcp
638 objectClass: top
639 objectClass: dhcpServer
640 dhcpServiceDN: cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
641 </pre></blockquote>
642
643 <p>The content of the dhcpServiceDN attribute is next used to locate the
644 subtree with DHCP configuration. The DHCP configuration subtree base
645 is located using a base scope search with base "cn=DHCP
646 Config,dc=skole,dc=skolelinux,dc=no" and filter
647 "(&(objectClass=dhcpService)(|(dhcpPrimaryDN=cn=dhcp,dc=skole,dc=skolelinux,dc=no)(dhcpSecondaryDN=cn=dhcp,dc=skole,dc=skolelinux,dc=no)))".
648 The search result is this entry:</p>
649
650 <blockquote><pre>
651 dn: cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
652 cn: DHCP Config
653 objectClass: top
654 objectClass: dhcpService
655 objectClass: dhcpOptions
656 dhcpPrimaryDN: cn=dhcp, dc=skole,dc=skolelinux,dc=no
657 dhcpStatements: ddns-update-style none
658 dhcpStatements: authoritative
659 dhcpOption: smtp-server code 69 = array of ip-address
660 dhcpOption: www-server code 72 = array of ip-address
661 dhcpOption: wpad-url code 252 = text
662 </pre></blockquote>
663
664 <p>Next, the entire subtree is processed, one level at the time. When
665 all the DHCP configuration is loaded, it is ready to receive requests.
666 The subtree in Debian Edu contain objects with object classes
667 top/dhcpService/dhcpOptions, top/dhcpSharedNetwork/dhcpOptions,
668 top/dhcpSubnet, top/dhcpGroup and top/dhcpHost. These provide options
669 and information about netmasks, dynamic range etc. Leaving out the
670 details here because it is not relevant for the focus of my
671 investigation, which is to see if it is possible to merge dns and dhcp
672 related computer objects.</p>
673
674 <p>When a DHCP request come in, LDAP is searched for the MAC address
675 of the client (00:00:00:00:00:00 in this example), using a subtree
676 scoped search with "cn=DHCP Config,dc=skole,dc=skolelinux,dc=no" as
677 the base and "(&(objectClass=dhcpHost)(dhcpHWAddress=ethernet
678 00:00:00:00:00:00))" as the filter. This is what a host object look
679 like:</p>
680
681 <blockquote><pre>
682 dn: cn=hostname,cn=group1,cn=THINCLIENTS,cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
683 cn: hostname
684 objectClass: top
685 objectClass: dhcpHost
686 dhcpHWAddress: ethernet 00:00:00:00:00:00
687 dhcpStatements: fixed-address hostname
688 </pre></blockquote>
689
690 <p>There is less flexiblity in the way LDAP searches are done here.
691 The object classes need to have fixed names, and the configuration
692 need to be stored in a fairly specific LDAP structure. On the
693 positive side, the invidiual dhcpHost entires can be anywhere without
694 the DN pointed to by the dhcpServer entries. The latter should make
695 it possible to group all host entries in a subtree next to the
696 configuration entries, and this subtree can also be shared with the
697 DNS server if the schema proposed above is combined with the dhcpHost
698 structural object class.
699
700 <p><strong>Conclusion</strong></p>
701
702 <p>The PowerDNS implementation seem to be very flexible when it come
703 to which LDAP schemas to use. While its "tree" mode is rigid when it
704 come to the the LDAP structure, the "strict" mode is very flexible,
705 allowing DNS objects to be stored anywhere under the base cn specified
706 in the configuration.</p>
707
708 <p>The DHCP implementation on the other hand is very inflexible, both
709 regarding which LDAP schemas to use and which LDAP structure to use.
710 I guess one could implement ones own schema, as long as the
711 objectclasses and attributes have the names used, but this do not
712 really help when the DHCP subtree need to have a fairly fixed
713 structure.</p>
714
715 <p>Based on the observed behaviour, I suspect a LDAP structure like
716 this might work for Debian Edu:</p>
717
718 <blockquote><pre>
719 ou=services
720 cn=machine-info (dhcpService) - dhcpServiceDN points here
721 cn=dhcp (dhcpServer)
722 cn=dhcp-internal (dhcpSharedNetwork/dhcpOptions)
723 cn=10.0.2.0 (dhcpSubnet)
724 cn=group1 (dhcpGroup/dhcpOptions)
725 cn=dhcp-thinclients (dhcpSharedNetwork/dhcpOptions)
726 cn=192.168.0.0 (dhcpSubnet)
727 cn=group1 (dhcpGroup/dhcpOptions)
728 ou=machines - PowerDNS base points here
729 cn=hostname (dhcpHost/domainrelatedobject/dnsDomainAux)
730 </pre></blockquote>
731
732 <P>This is not tested yet. If the DHCP server require the dhcpHost
733 entries to be in the dhcpGroup subtrees, the entries can be stored
734 there instead of a common machines subtree, and the PowerDNS base
735 would have to be moved one level up to the machine-info subtree.</p>
736
737 <p>The combined object under the machines subtree would look something
738 like this:</p>
739
740 <blockquote><pre>
741 dn: dc=hostname,ou=machines,cn=machine-info,dc=skole,dc=skolelinux,dc=no
742 dc: hostname
743 objectClass: top
744 objectClass: dhcpHost
745 objectclass: domainrelatedobject
746 objectclass: dnsDomainAux
747 associateddomain: hostname.intern
748 arecord: 10.11.12.13
749 dhcpHWAddress: ethernet 00:00:00:00:00:00
750 dhcpStatements: fixed-address hostname.intern
751 </pre></blockquote>
752
753 </p>One could even add the LTSP configuration associated with a given
754 machine, as long as the required attributes are available in a
755 auxiliary object class.</p>
756 </div>
757 <div class="tags">
758
759
760
761 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
762
763 </div>
764 </div>
765 <div class="padding"></div>
766
767 <div class="entry">
768 <div class="title"><a href="http://people.skolelinux.org/pere/blog/Combining_PowerDNS_and_ISC_DHCP_LDAP_objects.html">Combining PowerDNS and ISC DHCP LDAP objects</a></div>
769 <div class="date">2010-07-14 23:45</div>
770 <div class="body">
771 <p>For a while now, I have wanted to find a way to change the DNS and
772 DHCP services in Debian Edu to use the same LDAP objects for a given
773 computer, to avoid the possibility of having a inconsistent state for
774 a computer in LDAP (as in DHCP but no DNS entry or the other way
775 around) and make it easier to add computers to LDAP.</p>
776
777 <p>I've looked at how powerdns and dhcpd is using LDAP, and using this
778 information finally found a solution that seem to work.</p>
779
780 <p>The old setup required three LDAP objects for a given computer.
781 One forward DNS entry, one reverse DNS entry and one DHCP entry. If
782 we switch powerdns to use its strict LDAP method (ldap-method=strict
783 in pdns-debian-edu.conf), the forward and reverse DNS entries are
784 merged into one while making it impossible to transfer the reverse map
785 to a slave DNS server.</p>
786
787 <p>If we also replace the object class used to get the DNS related
788 attributes to one allowing these attributes to be combined with the
789 dhcphost object class, we can merge the DNS and DHCP entries into one.
790 I've written such object class in the dnsdomainaux.schema file (need
791 proper OIDs, but that is a minor issue), and tested the setup. It
792 seem to work.</p>
793
794 <p>With this test setup in place, we can get away with one LDAP object
795 for both DNS and DHCP, and even the LTSP configuration I suggested in
796 an earlier email. The combined LDAP object will look something like
797 this:</p>
798
799 <blockquote><pre>
800 dn: cn=hostname,cn=group1,cn=THINCLIENTS,cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
801 cn: hostname
802 objectClass: dhcphost
803 objectclass: domainrelatedobject
804 objectclass: dnsdomainaux
805 associateddomain: hostname.intern
806 arecord: 10.11.12.13
807 dhcphwaddress: ethernet 00:00:00:00:00:00
808 dhcpstatements: fixed-address hostname
809 ldapconfigsound: Y
810 </pre></blockquote>
811
812 <p>The DNS server uses the associateddomain and arecord entries, while
813 the DHCP server uses the dhcphwaddress and dhcpstatements entries
814 before asking DNS to resolve the fixed-adddress. LTSP will use
815 dhcphwaddress or associateddomain and the ldapconfig* attributes.</p>
816
817 <p>I am not yet sure if I can get the DHCP server to look for its
818 dhcphost in a different location, to allow us to put the objects
819 outside the "DHCP Config" subtree, but hope to figure out a way to do
820 that. If I can't figure out a way to do that, we can still get rid of
821 the hosts subtree and move all its content into the DHCP Config tree
822 (which probably should be renamed to be more related to the new
823 content. I suspect cn=dnsdhcp,ou=services or something like that
824 might be a good place to put it.</p>
825
826 <p>If you want to help out with implementing this for Debian Edu,
827 please contact us on debian-edu@lists.debian.org.</p>
828 </div>
829 <div class="tags">
830
831
832
833 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
834
835 </div>
836 </div>
837 <div class="padding"></div>
838
839 <div class="entry">
840 <div class="title"><a href="http://people.skolelinux.org/pere/blog/Idea_for_storing_LTSP_configuration_in_LDAP.html">Idea for storing LTSP configuration in LDAP</a></div>
841 <div class="date">2010-07-11 22:00</div>
842 <div class="body">
843 <p>Vagrant mentioned on IRC today that ltsp_config now support
844 sourcing files from /usr/share/ltsp/ltsp_config.d/ on the thin
845 clients, and that this can be used to fetch configuration from LDAP if
846 Debian Edu choose to store configuration there.</p>
847
848 <p>Armed with this information, I got inspired and wrote a test module
849 to get configuration from LDAP. The idea is to look up the MAC
850 address of the client in LDAP, and look for attributes on the form
851 ltspconfigsetting=value, and use this to export SETTING=value to the
852 LTSP clients.</p>
853
854 <p>The goal is to be able to store the LTSP configuration attributes
855 in a "computer" LDAP object used by both DNS and DHCP, and thus
856 allowing us to store all information about a computer in one place.</p>
857
858 <p>This is a untested draft implementation, and I welcome feedback on
859 this approach. A real LDAP schema for the ltspClientAux objectclass
860 need to be written. Comments, suggestions, etc?</p>
861
862 <blockquote><pre>
863 # Store in /opt/ltsp/$arch/usr/share/ltsp/ltsp_config.d/ldap-config
864 #
865 # Fetch LTSP client settings from LDAP based on MAC address
866 #
867 # Uses ethernet address as stored in the dhcpHost objectclass using
868 # the dhcpHWAddress attribute or ethernet address stored in the
869 # ieee802Device objectclass with the macAddress attribute.
870 #
871 # This module is written to be schema agnostic, and only depend on the
872 # existence of attribute names.
873 #
874 # The LTSP configuration variables are saved directly using a
875 # ltspConfig prefix and uppercasing the rest of the attribute name.
876 # To set the SERVER variable, set the ltspConfigServer attribute.
877 #
878 # Some LDAP schema should be created with all the relevant
879 # configuration settings. Something like this should work:
880 #
881 # objectclass ( 1.1.2.2 NAME 'ltspClientAux'
882 # SUP top
883 # AUXILIARY
884 # MAY ( ltspConfigServer $ ltsConfigSound $ ... )
885
886 LDAPSERVER=$(debian-edu-ldapserver)
887 if [ "$LDAPSERVER" ] ; then
888 LDAPBASE=$(debian-edu-ldapserver -b)
889 for MAC in $(LANG=C ifconfig |grep -i hwaddr| awk '{print $5}'|sort -u) ; do
890 filter="(|(dhcpHWAddress=ethernet $MAC)(macAddress=$MAC))"
891 ldapsearch -h "$LDAPSERVER" -b "$LDAPBASE" -v -x "$filter" | \
892 grep '^ltspConfig' | while read attr value ; do
893 # Remove prefix and convert to upper case
894 attr=$(echo $attr | sed 's/^ltspConfig//i' | tr a-z A-Z)
895 # bass value on to clients
896 eval "$attr=$value; export $attr"
897 done
898 done
899 fi
900 </pre></blockquote>
901
902 <p>I'm not sure this shell construction will work, because I suspect
903 the while block might end up in a subshell causing the variables set
904 there to not show up in ltsp-config, but if that is the case I am sure
905 the code can be restructured to make sure the variables are passed on.
906 I expect that can be solved with some testing. :)</p>
907
908 <p>If you want to help out with implementing this for Debian Edu,
909 please contact us on debian-edu@lists.debian.org.</p>
910
911 <p>Update 2010-07-17: I am aware of another effort to store LTSP
912 configuration in LDAP that was created around year 2000 by
913 <a href="http://www.pcxperience.com/thinclient/documentation/ldap.html">PC
914 Xperience, Inc., 2000</a>. I found its
915 <a href="http://people.redhat.com/alikins/ltsp/ldap/">files</a> on a
916 personal home page over at redhat.com.</p>
917 </div>
918 <div class="tags">
919
920
921
922 Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap</a>, <a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug</a>.
923
924 </div>
925 </div>
926 <div class="padding"></div>
927
928 <p style="text-align: right;"><a href="index.rss"><img src="http://people.skolelinux.org/pere/blog/xml.gif" alt="RSS feed" width="36" height="14"></a></p>
929
930 <div id="sidebar">
931
932
933
934
935
936 <h2>Archive</h2>
937 <ul>
938
939 <li>2010
940 <ul>
941
942 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/01/">January (2)</a></li>
943
944 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/02/">February (1)</a></li>
945
946 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/03/">March (3)</a></li>
947
948 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/04/">April (3)</a></li>
949
950 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/05/">May (9)</a></li>
951
952 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/06/">June (14)</a></li>
953
954 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/07/">July (12)</a></li>
955
956 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/08/">August (2)</a></li>
957
958 </ul></li>
959
960 <li>2009
961 <ul>
962
963 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/01/">January (8)</a></li>
964
965 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/02/">February (8)</a></li>
966
967 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/03/">March (12)</a></li>
968
969 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/04/">April (10)</a></li>
970
971 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/05/">May (9)</a></li>
972
973 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/06/">June (3)</a></li>
974
975 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/07/">July (4)</a></li>
976
977 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/08/">August (3)</a></li>
978
979 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/09/">September (1)</a></li>
980
981 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/10/">October (2)</a></li>
982
983 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/11/">November (3)</a></li>
984
985 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/12/">December (3)</a></li>
986
987 </ul></li>
988
989 <li>2008
990 <ul>
991
992 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/11/">November (5)</a></li>
993
994 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/12/">December (7)</a></li>
995
996 </ul></li>
997
998 </ul>
999
1000
1001
1002 <h2>Tags</h2>
1003 <ul>
1004
1005 <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (11)</a></li>
1006
1007 <li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
1008
1009 <li><a href="http://people.skolelinux.org/pere/blog/tags/aros">aros (1)</a></li>
1010
1011 <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (10)</a></li>
1012
1013 <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (35)</a></li>
1014
1015 <li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (38)</a></li>
1016
1017 <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (53)</a></li>
1018
1019 <li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (1)</a></li>
1020
1021 <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (8)</a></li>
1022
1023 <li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (3)</a></li>
1024
1025 <li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (8)</a></li>
1026
1027 <li><a href="http://people.skolelinux.org/pere/blog/tags/lenker">lenker (1)</a></li>
1028
1029 <li><a href="http://people.skolelinux.org/pere/blog/tags/ltsp">ltsp (1)</a></li>
1030
1031 <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (5)</a></li>
1032
1033 <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (71)</a></li>
1034
1035 <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (90)</a></li>
1036
1037 <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (14)</a></li>
1038
1039 <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (14)</a></li>
1040
1041 <li><a href="http://people.skolelinux.org/pere/blog/tags/reprap">reprap (10)</a></li>
1042
1043 <li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
1044
1045 <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (10)</a></li>
1046
1047 <li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (3)</a></li>
1048
1049 <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (13)</a></li>
1050
1051 <li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (1)</a></li>
1052
1053 <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (10)</a></li>
1054
1055 <li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (1)</a></li>
1056
1057 <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (7)</a></li>
1058
1059 </ul>
1060
1061 </div>
1062
1063 <p style="text-align: right">
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