OpenVPN behind NAT why speed is 0.5mB\sec?

Question

openvpn

If the hyper is on ESXi, it has hosts:
a) PfSense gateway
b) WS 2008r2 server OpenVPN and SMB
Clients on Windows 7
Naturally, PfSense forwards a port to the machine with the server. OpenVPN latest version, encryption off, compression off, tried both TCP and UDP, when copying over SMB more than 0.5 megabytes, the speed does not rise. The server has a gigabit, the client has a 100 megbit channel. I copy one big file. The server is at a decent distance from the client, about 2 tons, which is about 60 ms, maybe this is the case, or is the server behind NAT?

Answer 1

And on pfSense the speed is normal? If not, then you need to disable offload.
To disable hardware checksum offload, navigate under System > Advanced and select Networking tab. Under Networking Interfaces section check the Disable hardware checksum offload and click save. Reboot will be required after this step.

Answer 2

NAT definitely does not play any role, there is a suspicion that something is wrong with buffering

Answer 3

Try playing around with MTU.
In general - google, you are not the first to encounter this, there are articles on the network on this topic