SoftEther VPN User Forum

I'm not very savvy on this stuff, and I'm feeling my way through the setup process. I've got a Windows 2019 server spun up on a small cloud provider and I'm trying to get a functional VPN connection going.

I installed SoftEther VPN Server and set up the client on a Windows 10 machine here in my office. It connects, but ipconfig shows that the virtual NIC on the client is getting 169.254.92.197, but the DHCP in the VPN server shows a range of 192.168.30.10 to 192.168.30.200, while the Windows Server DHCP server shows 10.0.0.200 to 10.0.0.210. I even disabled both DHCP servers (in Windows and in SoftEther Server) and the client still gets this IP...

Where is it getting that address?

Well, I still don't know where the IP address was coming from, but once I enabled VirtualNAT, it's now receiving an IP from the correct range of the Virtual DHCP server, and now I'm able to connect properly.

I was just one step away, and didn't know it. Now I have to figure out what VirtualNAT is, and why it fixed my problem!!

Hi,

The IP address in the 169.254.x.x range has been assigned by the OS since it couldn't get an IP address from the DHCP server. If you didn't configure a bridge between your VPN server and the SoftEther application any client connecting to the VPN would need an IP address to be assigned manually (if possible). Therefore, when you enabled VirtualNAT the client was able to get an IP address assigned automatically in the range 192.168.30.10 to 192.168.30.200.

As a side note, you may encounter some issues where the CPU might peak at 90-100% CPU and stick there when you have 1-2 connections to the VPN server. If this becomes a problem, you can configure a standalone DHCP server and disable the VIrtualNAT and DHCP feature in SoftEther to fix the issue. We just implemented this change last week and now the CPU is running at 2-10% and sometimes we can see peeks at 20% during the initialization of the connection.