Windows 8 Pro (which is the version I have. I cannot comment on other versions) appears to have an issue with a normal OpenVPN tunnel. When using UDP, my VPN does not pass traffic. It does pass that traffic when I use TCP. Additionally, a Cisco SSL VPN (also UDP based) I use does not work. After browsing about a bit, I found that the UDP encapsulation settings have an effect on this. The registry setting which needs to be changed is:
After rebooting, both of my VPNs worked, fixing an issue which nearly made me abandon Windows 8.
I used the easy-rsa script to generate some new server certs recently, and found that my strongswan install on OpenWRT could not load the RSA key. This despite the fact that the same key works fine in OpenVPN on the same server. The interesting thing is that when I use the build-key-pkcs12 script instead of the build-key-server script, and then use openssl on the router to extract the cert and key, the key works. it is also a different size. The key kept coming up as 1704 bytes when using the server script, but 1669 bytes with the pkcs12 script. Since the pkcs12 script works, I suggest using it always. It generates the key and crt files any way, even though the extracted key file was a different size than the generated one with the same set of files. There must be a bug somewhere.