2

I am using Ubuntu 12.04 VPS to host a PPTP server for my own personal use. I have set it up using a script I have written myself which is drawn from various different tutorials I have come across online (http://www.markmearns.com/sandbox/pptp.sh).

The service installs fine and I can connect to it using any Windows machine using built-in VPN clients, via my iPhone and Android tablet. The connection works fine and all traffic is routed over the VPN. It works quickly and never drops out.

However, I have invested in a Mikrotik routerboard as I want a wifi network that just routes over the VPN. The router connects to the PPTP server, but after about 1m20s it disconnects and reconnects. The VPN server also does not exchange any data with the router.

The router and its settings are working fine as I can connect to commercial PPTP VPN services (like hidemyass.com) and the connection works fine and never drops out. This leads to me to believe that the router is not at fault, but my PPTP server is the problem.

Would be grateful if anyone could shed any light on this for me. The configuration is obviously that as seen in the script I have written.

Mark.

Improve this question

3 Answers 3

Reset to default
1

In my case, the cause was that the mtu size of the vpn, was bigger than the path to the host, so you can use traceroute to discover the lower mtu in the path to the host. the command is: traceroute <host> --mtu

In my case the lower MTU was 1280, so I used 1200 to make the vpn in the router configuration.

Improve this answer
0

Sounds to me like pptpd can't establish a connection and retries endless. Please check your system log. This can be done in in a terminal in real time via this command:

    tail -f /var/log/syslog

(Issue that command in terminal, then start pptpd in another terminal. Abort listing in first terminal with CRTL-C.)

PPTP uses GRE protocol. You must open your firewall for outbound connections via protocol 47 (GRE).

Improve this answer
1
  • Don't use PPTP! It's insecure and difficult to work with trough NAT. Use OpenVPN or IPSec, which is secure.
    – vidarlo
    Feb 12, 2017 at 16:16
0

Thanks for your suggestion - turns out it was more simple than I thought - in /etc/pptpd.conf I have specified the server IP to be the server's external IP whereas I should have made it a local IP, part of the same range as the client IPs. For some reason Windows clients will accept this, but others are more sensitive.

Mark.

Improve this answer
1
  • 1
    Please use the same user ID to ask and answer questions. Use the contact Us link below to ask the moderators to merge your two IDs.
    – user68186
    Mar 22, 2013 at 16:03

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .