vpn client cannot connect to windows 10 vpn host

Question

I am trying to create a remote connection to my home W10 Pro computer from my remote devices - an Android phone and a W10 Pro laptop. The laptop can connect remotely using RDP, but neither device can connect using the built-in W10 PPTP vpn. I used to be able to vpn-connect routinely with both devices, but no longer can. So, I assume my home router settings are correct as nothing has changed on the router. I wish I could tie the change to a modification in the host computer, but I was not that vigilant. Turning off the host Windows Defender firewall does not help. Any suggestions?

*** Move from Windows / Windows 10 / Internet and connectivity ***

Answer 1

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Answer 2

First, thanks for all the time and effort put into helping me with this problem. It is truly appreciated. In all of this testing, I continue to get a connection to the host computer that disconnects after less than a second. This leads me to suspect the cause lies somewhere other than the router or the router and host computer firewalls. Here are my results:

1. Re-enable WAN Miniport PPTP: Not possible. The icon for this adapter appears for less than a second and then disappears. Not enough time to access it or its settings.
2. Network Stack Reset: Done. Didn't work.
3. Event ID 10016 - COM Server Application Issue: Followed instructions.
   • I got the ownership and permissions for the CLSID and APPID changed to "Administrators," inherited to all sub-items, and "Full Control" permissions.
   • In Component Services>Computers>My Computer>DCOM Config, neither the specific CLSID nor APPID are present. Nothing to change.
   • When I click on DCOM Config, I get a series of "DCOM Configuration Warning!"s. These warnings are like this for 5 different CLSIDs, none of which match the Event ID 10016 CLSID.

I have so far clicked "No" in each instance. - I found very detailed step-by-step instructions for this process at - https://thegeekpage.com/fix-dcom-event-id-10016-error-in-windows-10/#google_vignetteThis link mentions enabling "Local Activation" for the Administrators group in "Immersive Shell" in the Component Services console. I tried and "Local Activation" was already enabled as specified. 4. GRE Packet Issue (Event ID 20209):
Here are the router confirguation pages for NAT and VPN Passthrough.

[![Image](https://learn-attachment.microsoft.com/api/attachments/67c897c4-b5c6-4654-97af-47bff144a482?platform=QnA "filestore.community.support.microsoft.com")  

[![Image](https://learn-attachment.microsoft.com/api/attachments/6a973b77-0e95-4b02-91e8-0ae0a705efdc?platform=QnA "filestore.community.support.microsoft.com")

VPN has always worked before using these settings. External Port 1723 is forwarded to internal Port 1723 as it has always been when VPN was working. I get the same negative results when the one and only firewall on the host computer is turned off.

5. Other Suggestions:

• The native VPN app on the Android phone will not let me use L2TP without an "L2TP Secret." I don't know what that is, I'm not sure the native Windows 10 VPN accepts L2TP and I'm not really interested in another VPN app.
• My Android phone software is up-to-date and it worked before.
• Can't find anything for NAT-T or NAT Traversal on the router.

Thanks again for your time, effort and generosity.

Answer 3

Based on your details, it seems that the VPN connection attempts are being disrupted by multiple issues. Here are the steps to address each problem you mentioned:

1. WAN Miniport Disappearing

This might indicate that there’s a conflict or issue with the PPTP VPN server. Here are a few things to try:

Re-enable WAN Miniport PPTP: Disable and re-enable the PPTP WAN Miniport adapter in the Network Connections window. It might help reset any connectivity issues.

Network Stack Reset: Open Command Prompt (as Administrator) and run:

netsh int ip reset

netsh winsock reset

This resets the network stack and might resolve any misconfigurations.

2. Event ID 10016 - COM Server Application Issue

This is a DCOM permission issue. To resolve this:

Open the Component Services tool (you can search for it in the start menu).

Navigate to Component Services > Computers > My Computer > DCOM Config.

Find the application associated with the CLSID mentioned in the error ({C2F03A33-21F5-47FA-B4BB-156362A2F239}).

Right-click the application and choose Properties.

Go to the Security tab, and under Launch and Activation Permissions, click Edit.

Grant the necessary permissions to Local Activation for your user (HOMEOFFICEVM\Bob_Neufeld).

3. GRE Packet Issue (Event ID 20209)

The issue here is the GRE protocol (protocol 47), which is necessary for PPTP connections. It seems that either:

Router Configuration: You need to ensure that your router allows GRE packets (protocol 47). Look for settings like PPTP Passthrough or GRE Passthrough and make sure they are enabled. You might also need to forward TCP port 1723 and GRE protocol (47) on your router.

Firewall Configuration: Check if there is a firewall blocking GRE. Make sure to allow GRE packets on both the Windows firewall and any third-party firewall.

4. Other Suggestions:

Test with L2TP or SSTP: If you continue to have issues with PPTP, consider testing with L2TP or SSTP, which are generally more reliable and secure.

Check for VPN Client Updates: Ensure that the VPN client you're using on your Android phone is up to date.

Verify NAT-T (NAT Traversal): Some routers may require NAT-T to be enabled for PPTP. Double-check your router's NAT settings to ensure this is enabled.

After trying these steps, let me know if the issue persists, and we can explore additional troubleshooting options.

Answer 4

Am working through some of your suggestions. When connecting from remote Android phone, I apparently can get through the router to my local network. The host computer Incoming Connections and WAN Miniport (PPTP) adapters show a connection for about a second or less. The Wan Miniport then disappears and Incoming Connections disconnects.

Also, the event viewer displayed the following messages in this order. I suspect the GRE message is a false indication. I have no idea what to do about the second message. I have changed ownership of the named CLSID and APPID to Administrator, but don't know what to do with the Component Services tool.

Event ID 20088 -- The Remote Access Server acquired IP Address 192.168.69.134 to be used on the Server Adapter.

Event ID 10016 -- The machine-default permission settings do not grant Local Activation permission for the COM Server application with CLSID 

{C2F03A33-21F5-47FA-B4BB-156362A2F239}

 and APPID 

{316CDED5-E4AE-4B15-9113-7055D84DCC97}

 to the user HOMEOFFICEVM\Bob_Neufeld SID (S-1-5-21-2886054563-1631771663-2082611330-1004) from address LocalHost (Using LRPC) running in the application container Microsoft.Windows.ShellExperienceHost_10.0.19041.5072_neutral_neutral_cw5n1h2txyewy SID (S-1-15-2-155514346-2573954481-755741238-1654018636-1233331829-3075935687-2861478708). This security permission can be modified using the Component Services administrative tool.

Event ID 20209 -- A connection between the VPN server and the VPN client 174.231.80.247 has been established, but the VPN connection cannot be completed. The most common cause for this is that a firewall or router between the VPN server and the VPN client is not configured to allow Generic Routing Encapsulation (GRE) packets (protocol 47).

Answer 5

Hello,

Thank you for reaching out,

It sounds like you're dealing with a PPTP VPN issue where you used to be able to connect without problems but now cannot. Since the router settings are unchanged and Windows Defender firewall was ruled out, we should explore a few other potential causes:

1. Check VPN Server Settings on Windows 10

Ensure that the VPN server is still enabled on your Windows 10 host. Go to Control Panel > Network and Sharing Center > Change adapter settings, then right-click on your VPN connection (or Incoming Connections) and select Properties.

Under the Networking tab, make sure that Allow callers to access my local network is checked.

2. Check for Windows Update or Changes

Even though you weren't vigilant, Windows 10 updates can sometimes cause changes to VPN services or networking settings. Try checking the system logs for any recent updates that may have affected the VPN functionality:

Go to Settings > Update & Security > Windows Update and see if there are any recent updates, especially security-related ones.

3. Enable PPTP in Router (if applicable)

Some routers have specific firewall or NAT settings that can block PPTP traffic (TCP port 1723 and GRE protocol 47). Ensure that your router has these ports forwarded correctly and that PPTP passthrough is enabled.

4. Check for Network Layer Issues

Network Isolation: Ensure that both devices (remote and host) are on the correct network (you mentioned a router, but VPN traffic may be getting blocked by local network rules).

VPN Server Configuration: Verify that the PPTP VPN server on your Windows 10 machine is properly configured and the IP range for VPN connections hasn't changed. You can reset the VPN settings by disabling and re-enabling the VPN server in Network Connections.

5. Recheck Firewall and Security Software

You mentioned turning off Windows Defender, but if you have any third-party security software installed (such as antivirus or a third-party firewall), it might still be blocking the connection. Disable or temporarily uninstall any additional security software to test.

6. Check for VPN Client Software Updates

Make sure that the VPN client software on both the Android device and the Windows 10 laptop is up to date. Sometimes, updates can address compatibility issues with Windows 10’s networking features.

7. Test Using Other VPN Protocols (as a workaround)

If you continue to have issues with PPTP, you could temporarily try using L2TP/IPsec or OpenVPN (which are generally more secure) to check if the problem lies with the PPTP protocol specifically.