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I am pretty new to Ubuntu and Linux, so forgive me if this is obvious. I set up a PPTP VPN connection the other day. It worked perfectly fine, but one day to the other, it didn't anymore. I used it on 12.04, and it stopped working there. I then upgraded to 13.04 and it still wont work. The only thing I changed was adding a second monitor (I'm now running dual monitors), but I doubt that that has anything to do with it. I also installed the recommended updates.

The syslog gave me this:

Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> Starting VPN service 'pptp'...
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> VPN service 'pptp' started  (org.freedesktop.NetworkManager.pptp), PID 4958
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> VPN service 'pptp' appeared; activating connections
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> VPN plugin state changed: init (1)
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> VPN plugin state changed: starting (3)
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> VPN connection 'us vpn' (Connect) reply received.
Sep 11 13:59:18 Veith-Ubuntu pppd[4962]: Plugin /usr/lib/pppd/2.4.5/nm-pptp-pppd-plugin.so loaded.
Sep 11 13:59:18 Veith-Ubuntu pppd[4962]: pppd 2.4.5 started by root, uid 0
Sep 11 13:59:18 Veith-Ubuntu pppd[4962]: Using interface ppp0
Sep 11 13:59:18 Veith-Ubuntu pppd[4962]: Connect: ppp0 <--> /dev/pts/1
Sep 11 13:59:18 Veith-Ubuntu pptp[4965]: nm-pptp-service-4958 log[main:pptp.c:314]: The synchronous pptp option is NOT activated
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]:    SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]:    SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found.
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <warn> /sys/devices/virtual/net/ppp0: couldn't determine device driver; ignoring...
Sep 11 13:59:18 Veith-Ubuntu pptp[4966]: nm-pptp-service-4958 warn[open_inetsock:pptp_callmgr.c:329]: connect: Connection refused
Sep 11 13:59:18 Veith-Ubuntu pptp[4966]: nm-pptp-service-4958 fatal[callmgr_main:pptp_callmgr.c:127]: Could not open control connection to 67.212.175.124
Sep 11 13:59:18 Veith-Ubuntu pptp[4965]: nm-pptp-service-4958 fatal[open_callmgr:pptp.c:487]: Call manager exited with error 256
Sep 11 13:59:18 Veith-Ubuntu pppd[4962]: Modem hangup
Sep 11 13:59:18 Veith-Ubuntu pppd[4962]: Connection terminated.
Sep 11 13:59:18 Veith-Ubuntu avahi-daemon[865]: Withdrawing workstation service for ppp0.
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]:    SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <warn> VPN plugin failed: 1
Sep 11 13:59:18 Veith-Ubuntu pppd[4962]: Exit.
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <warn> VPN plugin failed: 1
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <warn> VPN plugin failed: 1
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> VPN plugin state changed: stopped (6)
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> VPN plugin state change reason: 0
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <info> Policy set 'Kabelnetzwerkverbindung 1' (eth0) as default for IPv4 routing and DNS.
Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: <warn> error disconnecting VPN: Could not process the request because no VPN connection was active.
Sep 11 13:59:23 Veith-Ubuntu NetworkManager[885]: <info> VPN service 'pptp' disappeared

I googled a bit and uninstalled pptp-linux and network-manager-pptp. Then I reinstalled them. I still can't connect and I get the same code.

I definitely configuered everything right in the network manager, otherwise it wouldn't have worked in the first place. I MPPE activated, and checked all the settings 100 times. Another strange thing: When I tried it yesterday, it would give me the message that it connected for about half a second, only to be replaced by the "can't connect" Message right after. It doesn't do that today though. I also tried forbidding all the compression types.

I searched, but couldn't find anything (at least nothing I understood). Any help is greatly appreachiated!

Greetings

5

From the logs, is not possible to diagnose what really happened, but the PPTP protocol has known difficulty passing through firewalls, so that could be the case here.

For the PPTP VPN protocol, you need to have open port 1723. Different VPN protocols have different needs, see this summary:

PPTP:

  • IP Protocol=TCP, TCP Port number=1723 <- Used by PPTP control path
  • IP Protocol=GRE (value 47) <- Used by PPTP data path

L2TP:

  • IP Protocol Type=UDP, UDP Port Number=500 <- Used by IKEv1 (IPSec control path)
  • IP Protocol Type=UDP, UDP Port Number=4500 <- Used by IKEv1 (IPSec control path)
  • IP Protocol Type=UDP, UDP Port Number=1701 <- Used by L2TP control/data path
  • IP Protocol Type=50 <- Used by data path (ESP)

SSTP:

  • IP Protocol=TCP, TCP Port number=443 <- Used by SSTP control and data path

IKEv2:

  • IP Protocol Type=UDP, UDP Port Number=500 <- Used by IKEv2 (IPSec control path)
  • IP Protocol Type=UDP, UDP Port Number=4500 <- Used by IKEv2 (IPSec control path)
  • IP Protocol Type=UDP, UDP Port Number=1701 <- Used by L2TP control/data path
  • IP Protocol Type=50 <- Used by data path (ESP)

(Source)

To check if your ports are open or not, you can simply telnet to the VPN address.

> telnet ipaddress 1723

If the connection is okay, the VPN will respond.

If connection is not okay, you will get the connection timeout response after some delay. Try a different connection (mobile for example) to confirm the case.

If possible, contact your ISP to correct this.

Update: The command in your question fails with

Connection refused, Could not open control connection to xxx.xxx.xxx.xxx, and Call manager exited with error 256

so most likely, telnet will fail with connection refused (by host) as well and this could be different problem. Contact the VPN administrator to check the VPN logs from your IP address and the reason for refusal.

Update 2: You can follow the advice to fix the 256 error from this help page. It is basically these four steps:

  • Check ping to host
  • Check traceroute to host
  • Check telnet to host
  • Check supported protocols
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0

Have you called your VPN Server provider yet? There might be configuration changes. I have configured a PPTP VPN server on a CentOS box somewhere and while at home I'm using my Ubuntu 13.04 to dial in PPTP out of the box without issues.

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0

I'm not sure about what's happened but I finaly can connect VPN again after disable firewall with this command:

sudo ufw disable

I've tried many ways but it not work until the firewall was disabled. Hope it help you to debug further.

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  • 1
    Please don't post the same answer to multiple posts. Instead, if they are close enough to each other to be duplicates, flag the questions as duplicates. – Thomas Ward Oct 18 '19 at 0:01
-1

Your log is telling 3 things to me

  • Error message

    Sep 11 13:59:18 Veith-Ubuntu pptp[4965]: nm-pptp-service-4958 log[main:pptp.c:314]: The synchronous pptp option is NOT activated

    Check pptp log and debug why this option isn't activated.

  • Error message

    Sep 11 13:59:18 Veith-Ubuntu NetworkManager[885]: /sys/devices/virtual/net/ppp0: couldn't determine device driver; ignoring...

    Was ppp driver loaded properly

  • Make the VPN client and server configuration are exactly matched

| improve this answer | |
  • 1
    and that means what? Useless. – Dee Jul 4 '16 at 10:47
  • 1
    just confirmed that "The synchronous pptp option is NOT activated" message is on successful connection as well. => +1 down – Dee Jul 4 '16 at 12:36

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