jp2006
Posts: 1
Joined: Sun May 12, 2013 11:52 pm

Raspbian, Wifi, and VPNC?

Mon May 13, 2013 12:03 am

Hi,
I am fairly new to using Raspbian, and I have moderate experience using Linux distros (I am more skilled in Windows). I am having an issue that has me stumped. I have installed VPNC on Raspbian so I can connect to my work's Cisco VPN, and I am able to connect with no problems when I am using my eth0 connection. However, whenever I try to connect over wifi (wlan0), it immediately disconnects me from wifi and no connection is made. Looking at the logs, I am able to reach the VPN server, but my wifi seems to disconnect around the time that it asks for my VPN password. I am connecting to the VPN using IPSec with a group password. Anyone have any general ideas about what might be causing this? I can provide more detail, if needed. Thanks.

-JP

austinp
Posts: 15
Joined: Thu May 09, 2013 1:35 pm

Re: Raspbian, Wifi, and VPNC?

Mon May 13, 2013 4:37 am

Maybe check the MTU size ?

Geoff
Posts: 1
Joined: Wed Jun 12, 2013 12:35 pm

Re: Raspbian, Wifi, and VPNC?

Wed Jun 12, 2013 12:38 pm

JP:

I've run into the same issue. Have you found a solution?

Thanks,

Geoff

sudutha
Posts: 1
Joined: Fri Jan 03, 2014 5:11 am

Re: Raspbian, Wifi, and VPNC?

Fri Feb 21, 2014 6:47 am

Any solution to get around this problem? I am seeing the same issue.

profjws
Posts: 2
Joined: Wed Jun 25, 2014 11:32 pm

Re: Raspbian, Wifi, and VPNC?

Wed Jun 25, 2014 11:50 pm

Here's a fix (Raspbian 3.10.25+):

1. sudo nano /etc/wpa_supplicant/action_wpa.sh
2. insert a new line in this shell script just after the PATH=... line. On this new line, type:
exit 0
(that's the numeral 0).
3. Control-O to save, Control-X to exit.

now the command
sudo vpnc <your conf file>
should execute without error, and the command ifconfig will show a new network interface tun0.
To disconnect, sudo vpnc-disconnect
at which point ifconfig should reveal that the tun0 interface is gone.

Why this works:
It's "too many cooks in the kitchen". Both wpa_supplicant and ifplugd handle network interfaces in Raspbian. The wireless, usually on wlan0, is a "roaming" device. The wpa_action shell script's job is to make sure only one "roaming device" is on line at a time. But when vpnc creates the virtual tunnel tun0, the wpa_action script decides that wlan0 is no longer needed, and downs it--- just about the time your vpn connection is about to go "live".

Inserting "exit 0" in the shell script effectively disables wpa_action.sh, so that BOTH wlan0 and tun0 are up simultaneously, which is what you want. If at some time (importance of vpn) < (importance of roaming) then just remove the line and you're back to stock behaviour. A more elegant fix would abort the "ifdown wlan0" only when tun0 is coming up, but hey this is fast and got me on vpn with the Pi/WiFi.
Cheers!

binarynate
Posts: 1
Joined: Sun Jun 29, 2014 1:50 am

Re: Raspbian, Wifi, and VPNC?

Sun Jun 29, 2014 1:55 am

Thanks, profjws! I've been trying to resolve this same issue for a few hours now, and your solution did the trick.

profjws
Posts: 2
Joined: Wed Jun 25, 2014 11:32 pm

Re: Raspbian, Wifi, and VPNC?

Sun Aug 03, 2014 9:42 pm

Glad to hear it. I am way indebted to forums like this and glad to make a small contribution when I can... ;)

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