PPTP connection does not establish due to error: "Connection activation failed: the VPN service returned invalid configuration."

[R4kk00n]

The PPTP connection in question used to work on Vivid, now it does not connect after an upgrade to Wily.

That error description in the title comes from nmcli; it looks somewhat different in the notification popup

The relevant piece of syslog is in the attached syslog-snippet.txt

I'd say that the IP config as stated in the log looks valid to me

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: network-manager-pptp 0.9.10.0-1ubuntu1
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
ApportVersion: 2.19.1-0ubuntu4
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Oct 29 14:07:01 2015
InstallationDate: Installed on 2015-08-20 (69 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
SourcePackage: network-manager-pptp
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[thiagarcia (thiagarcia)]

After upgrading to VPN stopped working.
I removed the static routes and VPN returned to work.

Thank you

[lucuga (lucasugarte)]

After upgrading to VPN stopped working.
importance: Undecided → High

[berend (berenddeboer)]

I see a similar error message but when using openvpn.

[berend (berenddeboer)]

Like #3: after removing static routes, I can connect.

[berend (berenddeboer)]

And it seems I either had a wrong static route (most likely) or re-entering it fixed it.

[R4kk00n (r4kk00n)]

Well, if I could work without static routes, I wouldn't see an issue. And
removing and reentering them doesn't help: I can connect with an empty
list, but it refuses to when I add a route.
I have "use this connection only for resources on its own network" checked
On 1 Dec 2015 05:45, "berend" <email address hidden> wrote:

> And it seems I either had a wrong static route (most likely) or re-
> entering it fixed it.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1511330
>
> Title:
> PPTP connection does not establish due to error: "Connection
> activation failed: the VPN service returned invalid configuration."
>
> Status in network-manager-pptp package in Ubuntu:
> Confirmed
>
> Bug description:
> The PPTP connection in question used to work on Vivid, now it does not
> connect after an upgrade to Wily.
>
> That error description in the title comes from nmcli; it looks
> somewhat different in the notification popup
>
> The relevant piece of syslog is in the attached syslog-snippet.txt
>
> I'd say that the IP config as stated in the log looks valid to me
>
> ProblemType: Bug
> DistroRelease: Ubuntu 15.10
> Package: network-manager-pptp 0.9.10.0-1ubuntu1
> ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
> Uname: Linux 4.2.0-16-generic x86_64
> ApportVersion: 2.19.1-0ubuntu4
> Architecture: amd64
> CurrentDesktop: Unity
> Date: Thu Oct 29 14:07:01 2015
> InstallationDate: Installed on 2015-08-20 (69 days ago)
> InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
> SourcePackage: network-manager-pptp
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/network-manager-pptp/+bug/1511330/+subscriptions
>

[R4kk00n (r4kk00n)]

After some tinkering I've found a somewhat different workaround (of you might call it a fix) and a probable immediate cause of this behavior.

My VPN server has an address of 192.168.17.1 and it assings a range 192.168.17.33 - 192.168.17.62 to clients. I used to manually add the following routes (this is supposed to like the relevant dialog):
 Address Netmask Gateway Metric
 192.168.17.0 255.255.255.0 192.168.17.1 1
 172.16.32.0 255.255.252.0 192.168.17.1 1

This did work because (I believe, cannot really bother with testing now) Network Manager or PPTP plugin added a route to the VPN gateway (192.168.17.1 in my case). And it no longer does. Without this route further routes are considered invalid. This here might be a bug or it might have been redesigned — I don't know.

Luckily there is way to enter link scoped routes in that dialog, although unintuitive: you just leave the "Gateway" field empty. Like this:
 Address Netmask Gateway Metric
 192.168.17.0 255.255.255.0 1
 172.16.32.0 255.255.252.0 1
The "OK" button turns inactive after you delete a gateway, so you have to tab or click some other field for it to come back.

After this the connection works and the following routes get added to the routing table:
 > ip route
 default ...
 <vpn gateway external ip> via <your usual first hop router>
 ...
 172.16.32.0/22 dev ppp0 proto static scope link metric 1
 192.168.17.0/24 dev ppp0 proto static scope link metric 1
 192.168.17.35 dev ppp0 proto kernel scope link src 192.168.17.35 metric 50
 ...

Hope this helps someone else

[Olivier METRA (ometra-mc-media)]

Thanks R4kk00n, your workaround worked for me.

[Daniel Cantarín (omega-canta)]

This affected me yesterday (2020-01-14), and today was able to work around it with R4kk00n's comment instructions.

I'm using an up-to-date Ubuntu 18.04, so this bug is clearly still there. Some data from my setup:

Kernel: 4.15.0-74-generic x86_64
bits: 64
gcc: 7.4.0
Distro: Ubuntu 18.04.3 LTS

$ apt show network-manager-pptp
Package: network-manager-pptp
Version: 1.2.6-1
(...)

$ apt show network-manager
Package: network-manager
Version: 1.10.14-0ubuntu2
(...)