Problem establishing PPtP connection

Installing and Using OpenWrt
1

Hi geeks,
I am setting up PPtP connection between Openwrt 19.07 Banana PI based board and Ubuntu 22 pc. Connection get established but after 5-6 sec connection reset itself and this goes in loop.
from Log on Ubuntu side I observed bytes sent but no bytes received back. On wireshark I observed following packets where call-clear request originates and connection get reestablished but do not settle. For recent connection I have made Ubuntu pc as server(192.168.1.10) and Openwrt router as client(192.168.2.11).
following is os details-
root@LEDE:/#

ubus call system board
{
"kernel": "4.14.221",
"hostname": "LEDE",
"system": "ARMv7 Processor rev 3 (v7l)",
"model": "Bananapi BPI-R2",
"board_name": "bananapi,bpi-r2",
"release": {
"distribution": "OpenWrt",
"version": "19.07.7",
"revision": "r11306-c4a6851c72",
"target": "mediatek/mt7623",
"description": "OpenWrt 19.07.7 r11306-c4a6851c72"
}
}

If anyone want, I can provide whole configuration.

2

Upgrade, 19.07 is EOL.

3

In addition to what @frollic said... other things to consider:

don't use this protocol. It's not secure as it is trivially easy to crack. Use a modern protocol such as Wireguard.

Also... with respect to what is currently running on your BPI-R2, it's not official OpenWrt...

It appears you are using firmware that is not from the official OpenWrt project.

When using forks/offshoots/vendor-specific builds that are "based on OpenWrt", there may be many differences compared to the official versions (hosted by OpenWrt.org). Some of these customizations may fundamentally change the way that OpenWrt works. You might need help from people with specific/specialized knowledge about the firmware you are using, so it is possible that advice you get here may not be useful.

You may find that the best options are:

  1. Install an official version of OpenWrt, if your device is supported (see https://firmware-selector.openwrt.org).
  2. Ask for help from the maintainer(s) or user community of the specific firmware that you are using.
  3. Provide the source code for the firmware so that users on this forum can understand how your firmware works (OpenWrt forum users are volunteers, so somebody might look at the code if they have time and are interested in your issue).

If you believe that this specific issue is common to generic/official OpenWrt and/or the maintainers of your build have indicated as such, please feel free to clarify.

https://firmware-selector.openwrt.org/?version=23.05.5&target=mediatek%2Fmt7623&id=bananapi_bpi-r2

1 Like
4

Actually we are using banana PI with particular openwrt OS, it has been in the field , now client want to add PPtp VPN. I know its vulnerability.
Connection establishes but echo ping does not go through PPTP, which cause connection to reset, that is only issue. Openwrt has a section on this https://openwrt.org/docs/guide-user/services/vpn/pptp/client. I followed steps mentioned in this doc, but it could not be successful.

5

As we have established, this is a fork of OpenWrt, not firmware from the official project. This means that you need to ask the maintainers of that fork for help since theirs may have fundamental differences in behavior relative to official OpenWrt. Additionally, the version you have installed now is ancient and unsupported by the official project, which is why you are advised to upgrade to something more recent.

1 Like
6

Hi,
I got it done, actually with LAN to LAN interface it does not work resets. I used LTE interface of modem and setup PPTP vpn with remote end with port forwarding on 1723 and 47 ports. It works.