Android 4 ICS: VPN with IPsec PSK fails

February 11th, 2012 11 comments

I really like Android Ice Cream Sandwich on my Google Nexus S except for one thing: IPsec has a bug and is unusable. The bug was already reported in December 2011. Unfortunately there is no feedback from Google whatsoever. And it’s not like this bug is hard to verify. Install CentOS 6.2 on a VM, configure Openswan and you can see that setting up an IPsec PSK link between Android ICS and Openswan fails because Android ICS seems to mess up the payload which causes this error:

byte 7 of ISAKMP NAT-OA Payload must be zero, but is not

Starting in March both Samsung and HTC will start to roll out Android ICS to (some of) their current phones. Unless the Android Development Team fixes this bug there will be millions and millions of users who can no longer setup a secure tunnel using IPsec. Let’s hope it does not get to that.

Categories: Linux and Open Source Tags:

Increase the framerate on the F16 screencast recorder

December 9th, 2011 No comments

Fedora 16 comes with a built-in screencast recorder. By default the screencast recorder records the entire screen with a framerate of 15/sec. If you need a higher framerate then here’s what you do:

Open dconf-editor and go to org -> gnome -> shell -> recorder. Here you should see a number of options (file-extension, framerate and pipeline). Double click on the value of framerate and change it to your liking then press enter.

Next time you start (and stop) a screencast recording by pressing Control+Shift+Alt+R it will record with the new framerate you just entered. You can find your recording in your home directory. The name of the recording starts with shell-.

Want to know more about the keybindings used by the Shell? Check out the GNOME Shell Cheat Sheet.

The Ballmer Peak

December 1st, 2011 No comments
The Ballmer Peak by xkcd

The Ballmer Peak by xkcd

Further explanation here.

Categories: General Tags:

How to fix Fedora 16 boot problem when using RAID

November 30th, 2011 4 comments

If you use mdraid (Linux’ software RAID) and you want to install Fedora 16 with /boot, / and swap each in a RAID1 setup your box may not boot once the installation is finished. First go read bugzilla bug 750794 to understand what seems to be happening and why your box with shiny new Fedora 16 may not boot. Here is what I had to do to fix this problem. When you see the “Congratulations…” message at the end of the installation do not reboot. Instead go to the console (alt-f2) and do the following:

1. add the RAID modules to the grub2 environment

# echo 'GRUB_PRELOAD_MODULES="raid mdraid09 mdraid1x"' >> /etc/default/grub

2. generate a new grub2 config

# grub2-mkconfig -o /boot/grub2/grub.cfg

3. install grub2 again on both your RAID1 disks. Replace sda & sdb with your devices!!!

# grub2-install /dev/sda
# grub2-install /dev/sdb

Your box should now properly boot. If it does, enjoy your new Fedora 16 installation!

How to install Fedora 16 without GPT

November 30th, 2011 2 comments

Tip: if you want to install Fedora 16 without GPT labels then just boot with kernel option “nogpt” and it will revert to Fedora 15 behavior.