It’s annoying as hell ! Not only we need to patch to use Cisco client on 64 bit systems, recently i find out Cisco don’t support SMP (multi core) in its VPN client. It means after you load the cisco module, there’s a big chance you will run into a kernel panic: oops, the whole desktop freezes and the only thing you can do is a hard restart. Nice.
There’s a way out of this: turn off SMP aka turn one core of your CPU off before the module is loaded:
- sudo echo 0 > /sys/devices/system/cpu/cpu1/online (to turn the 2nd core off, replace cpu1 with cpu2 for 3rd core and so on)
- sudo echo 1 > /sys/devices/system/cpu/cpu1/online (turn it back on)
But why the hell do we have to use one core only ?? I mean, if we buy multi core CPU, we want to use it ! It’s ok if you only use VPN occasionally, however for folks like me who is forced to use VPN all day then this is just plain dumb. Good work Cisco, i will stick with vpnc afterall, ktnxbye !
Related posts:
- How to install Cisco VPN client on Ubuntu Jaunty Jackalope and Karmic Koala 64 bit
- Cisco VPN now runs on linux 64 bit systems
- Cisco VPN Client: Reason 412 – The remote peer is no longer responding
- With kernel 2.6.24 you will need a patch to install Cisco VPN Client
- How to fix Cisco VPN Client error 442 on Windows Vista
Comments 24
I’m Having this exact behaviour……
Posted 02 Dec 2008 at 10:21 am ¶Same issue here. This occurs only when I use wifi. Must be the Intel drivers as the suspend/hibernate also need to turn off the extra core to work. With ethernet, vpn seems to be ok.
Posted 11 Dec 2008 at 6:37 pm ¶on my computer (dell xpsm1330 ubuntu), vpn without wifi works, but vpn with wifi freezes my computer.
Posted 07 Jan 2009 at 10:51 pm ¶I will try your solution, because I am only
an occasional user.
I have tried
Posted 08 Jan 2009 at 11:12 pm ¶sudo echo 0 > /sys/devices/system/cpu/cpu1/online
But I have a bash message “Permission not allowed”
permission issue can be resolved via:
Posted 14 Feb 2009 at 7:47 pm ¶echo 1 | sudo tee /sys/devices/system/cpu/cpu1/online
Thanks for the Tip! I was actually enabling my cores via the BIOS Setup! Now, if theyh can just come out with a SMP-compatible Cisco VPN Client…
Posted 07 Apr 2009 at 3:51 pm ¶Well, I am having the same issue, but I am not sure mine is related to SMP…
I disabled the second CPU both through the BIOS and by using the suggested command (sudo echo 0 > /sys/devices/system/cpu/cpu1/online) without any success.
Some people mentionned it might be related to the Kernel version…
I just hope someone will come up with a good fix soon; I need the VPN to work…
Posted 09 Jul 2009 at 7:50 am ¶Finally fed up with Cisco vpn client, I tried VPNC. Had to configure it a bit, but finally worked like a charm
.
I followed the instructions here-
Posted 12 Jul 2009 at 11:19 am ¶http://www.toolsbysk.com/skforums/forum/Blah.pl?m-1247385296
Yep i definitely suggest vpnc over Cisco client. It can be integrated to NetworkManager so that you don’t need to type in the terminal. Another advatange is that vpnc runs in userland contrary to cisco client which having a kernel module that has to be recompiled everytime a new kernel is installed.
Posted 20 Jul 2009 at 5:43 pm ¶I was experiencing this same problem when using my wifi with Cisco VPN. Worked okay with ethernet interface. I tried your solution above and it worked!!! Been looking for a solution for the past 4 months. Thanks!!
Posted 03 Oct 2009 at 2:52 pm ¶This is before loading the kernel module???
This means that loading the module at startup will be stupid since I got kernel panic only while using the Wifi!
I remember I tried this long time ago, but I think that I was disabling the core while the module was loaded just after “vpnclient connect XXXX”. Can you confirm this?
Posted 03 Nov 2009 at 6:51 am ¶Hmm, i'm not sure whether a core should be turn off before or after loading Cisco module. But definitely before connecting.
If a cpu core must be turn off before module loading, you can add the off-command to “start” section in vpnclient_init script, and add on-command to “stop” section.
Posted 03 Nov 2009 at 4:13 pm ¶I am very interested in creating this script. Can you point me in a good direction to learn to do it?
/etc/init.d/vpn_init is a script, so , I could edit it?
Thanks for all your help!
Posted 03 Nov 2009 at 4:24 pm ¶Neither:
sudo echo 0 > /sys/devices/system/cpu/cpu1/online
or
echo 1 | sudo tee /sys/devices/system/cpu/cpu1/online
worked, both gave me permission problems!
Any ideas?
Posted 03 Nov 2009 at 7:04 pm ¶I've experiencing this freeze problem only when I use vpnclient over a wifi connection, not over a wired connection.
I've been using this solution for a while, after finding it here. I mentioned my problems to a friend of mine and he suggested playing with processor affinity – assigning the vpnclient to a particular CPU.
I've had a pretty good success this evening.
Check out the command
taskset
and assign vpnclient to processor 0
Posted 16 Dec 2009 at 7:02 pm ¶taskset -pc 0 vpnclient connect PCF_file
Very interesting ! Thanks a lot for mentioning this command. I haven't even heard about it before.
Posted 16 Dec 2009 at 8:04 pm ¶I've experiencing this freeze problem only when I use vpnclient over a wifi connection, not over a wired connection.
I've been using this solution for a while, after finding it here. I mentioned my problems to a friend of mine and he suggested playing with processor affinity – assigning the vpnclient to a particular CPU.
I've had a pretty good success this evening.
Check out the command
taskset
and assign vpnclient to processor 0
Posted 17 Dec 2009 at 3:02 am ¶taskset -pc 0 vpnclient connect PCF_file
Very interesting ! Thanks a lot for mentioning this command. I haven't even heard about it before.
Posted 17 Dec 2009 at 4:04 am ¶i haven't applied this line of command.i'm learning new things from you.thanks
Posted 22 Jan 2010 at 7:44 am ¶By far this article and the corresponding comments are the best info on this subject on the web. I've suffered with this issue for over a year – and still do unfort.
I've tried EVERYTHING. Can't get OpenVPN or vpnc to work. I get a panic with cisco with wifi or ethernet on a duo core system (Lenovo T60) or on a single cpu Comcrap Presario.
I have upgraded my kernel from 2.6.24.x to 2.6.31.x. Still no luck – though, interestingly enough Mandriva 2010 provides a cisco client with cpu1 shutdown commands built-in. Still doesn't help me though.
I've tried shutting down cpu1 on my Lenovo and I still have the issue. I haven't tried loading cisco before the shutdown nor have I tried the cpu affinitytaskset trick. Sounds promising.
Posted 25 Jan 2010 at 4:44 am ¶You are the man! Beau… Thanks for that tip.
so far so good!
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Posted 05 Jul 2010 at 7:40 am ¶Post a Comment