14.04 - VPN established but ssh kills it

Question

I have 14.04 LTS installed on my laptop (VMWare image) and I establish a VPN connection to my home. All that works fine, but when I want to use ssh on my laptop the VPN connection dies immediately.

How do I get ssh to work over a VPN connection?

I don't have this problem with a Windows 7 guest connecting to the same VPN server.

I see these errors in the syslog:

May 26 08:30:51 ubuntu pptp[6284]: nm-pptp-service-6262 log[logecho:pptp_ctrl.c:677]: Echo Request received.
May 26 08:30:51 ubuntu pptp[6284]: nm-pptp-service-6262 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 6 'Echo-Reply'
May 26 08:30:51 ubuntu pptp[6284]: nm-pptp-service-6262 log[logecho:pptp_ctrl.c:677]: Echo Reply received.
May 26 08:31:30 ubuntu pptp[6272]: nm-pptp-service-6262 warn[decaps_gre:pptp_gre.c:331]: short read (-1): Message too long
May 26 08:31:30 ubuntu pptp[6284]: nm-pptp-service-6262 log[callmgr_main:pptp_callmgr.c:234]: Closing connection (unhandled)
May 26 08:31:30 ubuntu pptp[6284]: nm-pptp-service-6262 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request'
May 26 08:31:30 ubuntu pptp[6284]: nm-pptp-service-6262 log[call_callback:pptp_callmgr.c:79]: Closing connection (call state)
May 26 08:31:30 ubuntu pppd[6266]: Modem hangup
May 26 08:31:30 ubuntu pppd[6266]: Connect time 1.6 minutes.
May 26 08:31:30 ubuntu pppd[6266]: Sent 6871 bytes, received 6572 bytes.
May 26 08:31:30 ubuntu pppd[6266]: MPPE disabled

Answer 1

Try to make vpn connection with this script, not with NM.

Maybe on this way all will work.

Create file with some name and put in

nano name_of_script

script

#!/bin/bash
function routeadd {
    route add -host xxx.xxx.xxx.xxx dev ppp0
    route add -net xxx.xxx.xxx.xxx/xx dev ppp0
}
function makepptp {
   echo pty \"pptp xxx.xxx.xxx.xxx --nolaunchpppd\" >> /etc/ppp/peers/vpn;
   echo remotename PPTP >> /etc/ppp/peers/vpn;
   echo require-mppe-128 >> /etc/ppp/peers/vpn;
   echo file /etc/ppp/options.pptp >> /etc/ppp/peers/vpn;
   echo ipparam vpn >> /etc/ppp/peers/vpn;
pppd call vpn &
}
if [ -a /etc/ppp/chap-secrets ];
        then
        rm /etc/ppp/chap-secrets
    echo $1 PPTP $2 '*' >> /etc/ppp/chap-secrets;
else
    echo $1 PPTP $2 '*' >> /etc/ppp/chap-secrets;
fi

if [ -e /etc/ppp/peers/vpn ];
    then
    rm /etc/ppp/peers/vpn;
    echo name $1 >> /etc/ppp/peers/vpn;
    makepptp;
    sleep 8;
    routeadd;
else
    echo name $1 >> /etc/ppp/peers/vpn;
    makepptp;
    sleep 8;
    routeadd;
fi

In script change you host ip and add network or/and host witch you wish to connect via vpn

Usage:

sudo /path_to_script/name_of_script username password

note: set execute permision to script

Answer 2

I had the same problem and the following approach worked for me:

"Use Point-to-Point encryption(MPPE)" must be selected

Note: one or more of MSCHAP authentication methods should be selected before.

Of course this is dependent to your VPN server settings as well.