SoftEther VPN FAQ

Moved here from original gist

Cheat sheet for a few quirks I discovered in SoftEther VPN that are not immediately obvious.

Routing and Remote Access

If you enable the “Routing and Remote Access” service in Windows (tested on 10) it causes the SoftEther VPN client running on that machine to drop packets.

VPN concentrator

This is tested with SecureNAT enabled.

If you wish to run a SoftEther VPN client and a SoftEther VPN server on the same Linux or Windows host then you probably want the SoftEther VPN server to follow the system route table.

To achieve this you must forcefully prevent SoftEther VPN server from using KernelModeSecureNAT or RawIpModeSecureNAT. This is because they communicate using low level APIs directly to the drivers.

You need to open the “Edit Virtual Hub Extended Option List” and set DisableKernelModeSecureNAT and DisableRawIpModeSecureNAT to 1.

This ensures the virtual SecureNAT uses “UserMode”. More documentation available here in Japanese: ja.softether.org/4-docs/3-kb/VPNFAQ036

The following issue helped pointed me to that page which I then translated using google: SoftEtherVPN/issues/349#issuecomment-349570182

Linux VPN client drops packets

Try setting the following setting under “Advanced Settings” of the connection properties dialogue Disable UDP Acceleration.