Played around with it tonight. Managed to get it working on my Netgear WNDR3700v2 running DD-WRT (v3.0-r27456 (06/27/15) std) using the guide on the following site. https://www.expressvpn.com/tutorials/dd ... rs_openvpn
Two differences was enabling pass authentication so you can enter your sonic username and password. And the "mss-fix/fragment across the tunnel" was left blank. Or in my case I didn't have that entry or it was renamed to "Tunnel UDP Fragment" which I left blank.
Very interesting transfer speeds with VPN.
Speedtest.net ~17.65mbps down, 1.65mbps up
speedof.me ~11.57mbps down, 1.78mbps up
And to just compare without VPN.
Speedtest.net ~23.05mbps down, 1.73mbps up
speedof.me ~24.51mbps down, 1.83mbps up
Something I noticed while using a test router running DD-WRT is that it would fail the handshake if it wasn't the device that was chosen for the IP passthru on the NVG589. On the same test router it would also would fail to resolve the server name before even attempting to make a handshake when I switched to the IP.
Maybe someone else can find some better optimized settings from here. I never touched OpenVPN until tonight.