How to debug VPN Connection Issues (13.10)
Solution 1
Now let me answer your specific problem.
as it seems there are some warnings in your log. I will try to investigate them one by one.
- You have a line saying:
NetworkManager[751]: Policy set 'VM529841-5G' (eth1) as default for IPv4 routing and DNS.
I assume that VPN should use tunnel interface instead of ethernet1. so please try unticking "use this connection only for resources on its network" in Network Connections -> VPN -> edit -> Ipv4 settings tab -> Routes.
- Another line says:
VPN connection 'Fluency Labs VPN' (IP Config Get) timeout exceeded
remove the wins entry from /etc/nsswitch.conf hosts line
- Another line says:
/sys/devices/virtual/net/ppp0: couldn't determine device driver; ignoring...
following this question It Looks like there must be a bug in libgcrypt11=1.5.0-3ubuntu2.2. After rolling back to libgcrypt11=1.5.0-3ubuntu2.1 things are working again...
sudo apt-get install libgcrypt11=1.5.0-3ubuntu2.1
I hope that saves you
Solution 2
Answering your question title is a bit different from your specific problem. I will start by answering the question title: how to debug vpn connection issues?
- First You need to run pppd in debug mode by passing debug option.
sudo grep debug /etc/rsyslog.d/*
the output might be something like this:
/etc/rsyslog.d/50-default.conf:#*.=debug;\
/etc/rsyslog.d/50-default.conf:# news.none;mail.none -/var/log/debug
/etc/rsyslog.d/50-default.conf:# *.=debug;*.=info;\
/etc/rsyslog.d/50-default.conf: *.=debug;*.=info;\
so /var/log/debug is your debug file.
- Start pppd with debug option
sudo pppd debug call /path/to/yourvpn.vpn
- Watch Debug Log
tail -f /var/log/debug
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Craig Warren
I am a Software Engineer based in Scotland, working in London. I primarily work with Android/Java but have experience with the Microsoft .Net technology stack, including an MCTS in ASP.Net. I also occasionally build simply websites in PHP. Scripting in Python, Ruby and Perl. Plenty of experience with SQL database (Oracle, MS and MySQL) used for relational data and data warehousing. I graduated from Heriot Watt University in Edinburgh with a MEng Distinction in Software Engineering.
Updated on September 18, 2022Comments
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Craig Warren almost 2 years
I'm trying to connect to a work VPN, but every time I attempt to connect it fails. The VPN has been configured in the Network Manager UI and the connection is being started from there too. I have checked the system logs and see the following:
Jan 28 08:29:09 cwlt NetworkManager[751]: <info> Starting VPN service 'pptp'... Jan 28 08:29:09 cwlt NetworkManager[751]: <info> VPN service 'pptp' started (org.freedesktop.NetworkManager.pptp), PID 6383 Jan 28 08:29:09 cwlt NetworkManager[751]: <info> VPN service 'pptp' appeared; activating connections Jan 28 08:29:09 cwlt NetworkManager[751]: <info> VPN plugin state changed: starting (3) Jan 28 08:29:09 cwlt NetworkManager[751]: <info> VPN connection 'VPN' (Connect) reply received. Jan 28 08:29:09 cwlt pppd[6387]: Plugin /usr/lib/pppd/2.4.5/nm-pptp-pppd-plugin.so loaded. Jan 28 08:29:09 cwlt pppd[6387]: pppd 2.4.5 started by root, uid 0 Jan 28 08:29:09 cwlt pppd[6387]: using channel 10 Jan 28 08:29:09 cwlt pppd[6387]: Using interface ppp0 Jan 28 08:29:09 cwlt pppd[6387]: Connect: ppp0 <--> /dev/pts/4 Jan 28 08:29:09 cwlt NetworkManager[751]: SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0) Jan 28 08:29:09 cwlt NetworkManager[751]: SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found. Jan 28 08:29:09 cwlt NetworkManager[751]: <warn> /sys/devices/virtual/net/ppp0: couldn't determine device driver; ignoring... Jan 28 08:29:09 cwlt pptp[6391]: nm-pptp-service-6383 log[main:pptp.c:314]: The synchronous pptp option is NOT activated Jan 28 08:29:09 cwlt whoopsie[1138]: online Jan 28 08:29:09 cwlt pptp[6405]: nm-pptp-service-6383 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 1 'Start-Control-Connection-Request' Jan 28 08:29:09 cwlt pptp[6405]: nm-pptp-service-6383 log[ctrlp_disp:pptp_ctrl.c:739]: Received Start Control Connection Reply Jan 28 08:29:09 cwlt pptp[6405]: nm-pptp-service-6383 log[ctrlp_disp:pptp_ctrl.c:773]: Client connection established. Jan 28 08:29:10 cwlt pptp[6405]: nm-pptp-service-6383 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 7 'Outgoing-Call-Request' Jan 28 08:29:10 cwlt whoopsie[1138]: online Jan 28 08:29:10 cwlt pptp[6405]: nm-pptp-service-6383 log[ctrlp_disp:pptp_ctrl.c:858]: Received Outgoing Call Reply. Jan 28 08:29:10 cwlt pptp[6405]: nm-pptp-service-6383 log[ctrlp_disp:pptp_ctrl.c:897]: Outgoing call established (call ID 0, peer's call ID 42341). Jan 28 08:29:49 cwlt NetworkManager[751]: <warn> VPN connection 'Fluency Labs VPN' (IP Config Get) timeout exceeded. Jan 28 08:29:49 cwlt NetworkManager[751]: <info> Policy set 'VM529841-5G' (eth1) as default for IPv4 routing and DNS. Jan 28 08:29:49 cwlt pppd[6387]: Terminating on signal 15 Jan 28 08:29:49 cwlt pppd[6387]: Connection terminated. Jan 28 08:29:49 cwlt avahi-daemon[709]: Withdrawing workstation service for ppp0. Jan 28 08:29:49 cwlt NetworkManager[751]: SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0) Jan 28 08:29:49 cwlt pppd[6387]: Child process /usr/sbin/pptp xxx.xxx.xxx.xxx --nolaunchpppd --loglevel 0 --logstring nm-pptp-service-6383 (pid 6389) terminated with signal 15 Jan 28 08:29:49 cwlt pppd[6387]: Exit. Jan 28 08:29:49 cwlt pptp[6391]: nm-pptp-service-6383 warn[decaps_hdlc:pptp_gre.c:204]: short read (-1): Input/output error Jan 28 08:29:49 cwlt pptp[6391]: nm-pptp-service-6383 warn[decaps_hdlc:pptp_gre.c:216]: pppd may have shutdown, see pppd log Jan 28 08:29:49 cwlt pptp[6405]: nm-pptp-service-6383 log[callmgr_main:pptp_callmgr.c:234]: Closing connection (unhandled) Jan 28 08:29:49 cwlt pptp[6405]: nm-pptp-service-6383 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request' Jan 28 08:29:49 cwlt pptp[6405]: nm-pptp-service-6383 log[call_callback:pptp_callmgr.c:79]: Closing connection (call state) Jan 28 08:29:54 cwlt NetworkManager[751]: <info> VPN service 'pptp' disappeared
I've deliberately hidden the ip-address here so don't worry about that. I don't really know what is going wrong here, so if someone could point me in the right direction that would be great.
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suqed over 10 yearsMaybe following solution for Ubuntu 12.04 does help you: How To Debug and Fix PPTP/VPN Client Connection -- Regards.
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Craig Warren over 10 yearsThanks for your help, I haven't actually checked this answer as I was able to make my vpn work by removing all the config files... I have noticed that my libgcrypt versions is on 3ubuntu3 so that's a big possibility.
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gb96 about 9 yearsWhen VPN is configured using the NetworkManager its settings end up in
/etc/NetworkManager/system-connections/your-vpn
. The commandsudo pppd call /path/to/yourvpn.vpn
fails because the last argument may not begin with a / but instead must match a filename within /etc/ppp/peers. Can anyone please clarify this confusion?