Issue where windows11 pc connected to openwrt router cannot connect to vpn like pptp, l2tp etc

Installing and Using OpenWrt
1

issue where windows11 pc connected to openwrt router cannot connect to vpn like pptp, l2tp etc

The router is a CMCC RAX3000M model, with the following firmware version:OpenWrt 23.05.4 r24012-d8dd03c46f / LuCI openwrt-23.05 branch git-24.086.45142-09d5a38

The test environment is windows11 connected by LAN (I also tested it in wireless environment but it is the same).

I tried to connect to a Synology VPN server, but all protocols failed, including PPTP and L2TP.

I opened the GRE protocol and the 1723 port firewall, but I still can't connect to the VPN server at my home.

Attached is the event log for Windows 11 below.
I was able to connect to the VPN from my desktop through all the routers I have (asus, iptime), but only in open wrt environment I am unable to connect to synology vpn server.

Title: PPTP VPN Connection Failure - Error Codes 619 and 829

Description:

I'm experiencing issues establishing a PPTP VPN connection to my OpenWRT router. The Windows Event Viewer shows the following errors:

Event Log 1:

Log Name:      Application
Source:        RasClient
Date:          2024-08-28 PM 5:43:54
Event ID:      20227
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      APP01
Description:
CoId={016ABAC6-F91C-0006-F592-8B011CF9DA01}: The user APP01\m3 dialed a connection named pptp which has failed. The error code returned on failure is 619.

content_copyUse code with caution.

Event Log 2:

Log Name:      Application
Source:        RasClient
Date:          2024-08-28 PM 5:43:54
Event ID:      20291
Task Category: None
Level:         Information
Keywords:      Classic
User:          N/A
Computer:      APP01
Description:
pptp has encountered an error.

content_copyUse code with caution.

Event Log 3:

Log Name:      Application
Source:        RasClient
Date:          2024-08-28 PM 5:43:54
Event ID:      20226
Task Category: None
Level:         Information
Keywords:      Classic
User:          N/A
Computer:      APP01
Description:
CoId={016ABAC6-F91C-0006-F592-8B011CF9DA01}: The user APP01\m3 dialed a connection named pptp which has terminated. The reason code returned on termination is 829.

content_copyUse code with caution.

Event Log 4 - 7: (These logs show the connection initiation attempts and details, which were already analyzed in previous responses.)

Troubleshooting Steps Taken:

  • Confirmed PPTP Passthrough is enabled on OpenWRT.

  • Verified necessary firewall rules for PPTP (TCP 1723, GRE protocol 47) are in place.

  • Checked VPN server IP address and credentials.

  • Ensured no network connectivity issues between the server and client.

Issue:

Despite these steps, the VPN connection still fails with error codes 619 and 829.

2

you need to install the nat helpers

opkg update 
opkg install kmod-nf-nathelper-extra

not sure if it's still needed to run but I have old notes for

echo "net.netfilter.nf_conntrack_helper = 1" >> /etc/sysctl.d/local.conf
/etc/init.d/sysctl restart
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3

It won't help much because (despite the package info) nf_conntrack_proto_gre and nf_nat_proto_gre are no longer part of kmod-nf-nathelper-extra.

However, with l2tp there should be no problem.

4

well I could not connect to PPTP without it V23.05.2

5

The question is, can you connect after installing it, because as I said, proto_gre is no longer included in the package.

6

It was required earlier this year for V23.05.2 to connect to a PPTP connection
I can not test this as PPTP it's no longer in use as of last month
so didn't bother after upgrade to V23.05.4
no I didn't use V23.05.3 I went from .2 to .4

7

I followed your instructions and got a perfect PPTP connection. Thank you so much.
The package was already installed, but the PPTP connection was established immediately after the command.

1 Like