We are working on setting up two private networks linked by a public network which is fast (1 Gbit/s) but potentially insecure. Since the hosts on our two networks need to talk to each other, and do so securely, we have decided to use OpenVPN to connect them, making one gateway a server and the other a client. The connectivity part was easy to establish and worked like a charm. The only problem was, and is, performance.
We have two old PIII-class machines that are being tested for the role of the gateways. We have put new 1 Gbit NIC's in them and they work
Why you are using such a antique hardware?
-- Eero