X-Git-Url: https://pere.pagekite.me/gitweb/homepage.git/blobdiff_plain/25fcaada458d0606c60bce4845974e127080f197..e68cf303a23c4cf014d8200d9c6c21049b62c117:/blog/index.html diff --git a/blog/index.html b/blog/index.html index 199bd4bc72..84490ee901 100644 --- a/blog/index.html +++ b/blog/index.html @@ -19,6 +19,91 @@ +
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Hvor godt fungerer Linux-klienter mot MS Exchange?
+
26th November 2013
+

Jeg +skrev +i juni om protestene på planene til min arbeidsplass, +Universitetet i Oslo, om å gå bort fra +fri programvare- og åpne standardløsninger for å håndtere epost, +vekk fra IETF-standarden SIEVE for filtrering av epost og over til +godseide spesifikasjoner og epostsystemet Microsoft Exchange. +Protestene har fått litt ny omtale i media de siste dagene, i tillegg +til de oppslagene som kom i mai.

+ + + +

Prosjektledelsen har fortalt at dette skal fungere like godt for +Linux-brukere som for brukere av Microsoft Windows og Apple MacOSX, +men jeg lurer på hva slags erfaringer Linux-brukere i eksisterende +miljøer som bruker MS Exchange har gjort. Hvis du har slik erfaring +hadet det vært veldig fint om du kan send et leserbrev til +Uniforum og fortelle om hvor +greit det er å bruke Exchange i kryss-platform-miljøer? De jeg har +snakket med sier en greit får lest e-posten sin hvis Exchange har +slått på IMAP-funksjonalitet, men at kalender og møtebooking ikke +fungerer godt for Linux-klienter. Jeg har ingen personlig erfaring å +komme med, så jeg er nysgjerrig på hva andre kan dele av erfaringer +med universitetet.

+ +

Mitt ankerpunkt mot å bytte ut fri programvare som fungerer godt +med godseid programvare er at en mister kontroll over egen +infrastruktur, låser seg inn i en løsning det vil bli dyrt å komme ut +av, uten at en får funksjonalitet en ikke kunne skaffet seg med fri +programvare, eventuelt videreutviklet med de pengene som brukes på +overgangen til MS Exchange. Personlig planlegger jeg å fortsette å +laste ned all eposten min til lokal maskin for indeksering og lesing +med notmuch, så jeg håper jeg +ikke blir veldig skadelidende av overgangen.

+ +

Underskriftslista +for oss som er mot endringen, som omtales i artiklene, er fortsatt +åpen for de som vil signere på oppropet. Akkurat nå er det 298 +personer som har signert.

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+ + + Tags: norsk, standard. + + +
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New chrpath release 0.15
24th November 2013
@@ -764,100 +849,6 @@ over.

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A Raspberry Pi based batman-adv Mesh network node
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21st October 2013
-

The last few days I have been experimenting with -the -batman-adv mesh technology. I want to gain some experience to see -if it will fit the -Freedombox project, and together with my neighbors try to build a -mesh network around the park where I live. Batman-adv is a layer 2 -mesh system ("ethernet" in other words), where the mesh network appear -as if all the mesh clients are connected to the same switch.

- -

My hardware of choice was the Linksys WRT54GL routers I had lying -around, but I've been unable to get them working with batman-adv. So -instead, I started playing with a -Raspberry Pi, and tried to -get it working as a mesh node. My idea is to use it to create a mesh -node which function as a switch port, where everything connected to -the Raspberry Pi ethernet plug is connected (bridged) to the mesh -network. This allow me to hook a wifi base station like the Linksys -WRT54GL to the mesh by plugging it into a Raspberry Pi, and allow -non-mesh clients to hook up to the mesh. This in turn is useful for -Android phones using the Serval -Project voip client, allowing every one around the playground to -phone and message each other for free. The reason is that Android -phones do not see ad-hoc wifi networks (they are filtered away from -the GUI view), and can not join the mesh without being rooted. But if -they are connected using a normal wifi base station, they can talk to -every client on the local network.

- -

To get this working, I've created a debian package -meshfx-node -and a script -build-rpi-mesh-node -to create the Raspberry Pi boot image. I'm using Debian Jessie (and -not Raspbian), to get more control over the packages available. -Unfortunately a huge binary blob need to be inserted into the boot -image to get it booting, but I'll ignore that for now. Also, as -Debian lack support for the CPU features available in the Raspberry -Pi, the system do not use the hardware floating point unit. I hope -the routing performance isn't affected by the lack of hardware FPU -support.

- -

To create an image, run the following with a sudo enabled user -after inserting the target SD card into the build machine:

- -

-% wget -O build-rpi-mesh-node \
-    https://raw.github.com/petterreinholdtsen/meshfx-node/master/build-rpi-mesh-node
-% sudo bash -x ./build-rpi-mesh-node > build.log 2>&1
-% dd if=/root/rpi/rpi_basic_jessie_$(date +%Y%m%d).img of=/dev/mmcblk0 bs=1M
-%
-

- -

Booting with the resulting SD card on a Raspberry PI with a USB -wifi card inserted should give you a mesh node. At least it does for -me with a the wifi card I am using. The default mesh settings are the -ones used by the Oslo mesh project at Hackeriet, as I mentioned in -an -earlier blog post about this mesh testing.

- -

The mesh node was not horribly expensive either. I bought -everything over the counter in shops nearby. If I had ordered online -from the lowest bidder, the price should be significantly lower:

- -

- - - - - - - - -
SupplierModelNOK
TeknikkmagasinetRaspberry Pi model B349.90
TeknikkmagasinetRaspberry Pi type B case99.90
LefdalJensen Air:Link 25150295.-
Clas OhlsonKingston 16 GB SD card199.-
Total cost943.80

- -

Now my mesh network at home consist of one laptop in the basement -connected to my production network, one Raspberry Pi node on the 1th -floor that can be seen by my neighbor across the park, and one -play-node I use to develop the image building script. And some times -I hook up my work horse laptop to the mesh to test it. I look forward -to figuring out what kind of latency the batman-adv setup will give, -and how much packet loss we will experience around the park. :)

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- - - Tags: english, freedombox, mesh network, nuug. - - -
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