Connection to PPTP server drops continually

Question

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.

Solution

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.

Comments

[user68186]

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.

[vidarlo]

Don't use PPTP! It's insecure and difficult to work with trough NAT. Use OpenVPN or IPSec, which is secure.