Networking – Remote Access error 789

networkingremotevpn

I need some help with our VPN solution, if you would be so kind 🙂

The full error message is

Remote Access error 789 – The L2TP connection attempt failed because the security layer encountered a processing error during initial negotiations with the remote computer

This only happens on one single users PC, and only when he is on his home network. No other clients is having issues.

I've tried to change the network profile from Public to Private. Did not help. I've also tried to change it to Domain network, and that didn't help either.

We've got Symantec Antivirus on all machines, but again, there hasn't been any troubles like this on ANY other client.

The firewall SEEMS to be turned off when on Private and Domain network, but not on Public. But this is controlled by the antivirus.

I haven't got immediate access to his router, and would prefer if this could be leaved "untouched"

The connection is a L2TP/IPsec, requires encryption, with a Pre-shared key.
The clients use a batch, which is using rasdial to connect.

The server itself, is a Meraki firewall.

Please, ask any questions if you have any.

Best Answer

It can be a protocol incompatibility (AES/3DES, etc).

  • Check the firewall settings
  • UDP port 500 and 4500 should be NATed and 1701 forwarded
  • Run services.msc as administrator.
  • Find “IKE and AuthIP IPsec Keying Modules” and “IPsec Policy Agent” Check the status, right click to “restart” if it states “started” If the “started” option is disabled, enable it.
  • Right click and scroll down and click on Properties Select the “Startup type” and change it to “Automatic” and save Restart your VPN and it should work smoothly now as the protocol settings should reset to default
  • If that does not work, you will have to manually set the encryption method for both server and clients so they are compatible.
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