翻牆被攔科普

https://theinitium.com/article/20150904-mainland-greatfirewall/

https://openvpn.net/index.php/open-source/documentation/security-overview.html
https://en.wikipedia.org/wiki/OpenVPN

這就難怪OpenVPN 會被攔

OpenVPN has two authentication modes:

• Static Key -- Use a pre-shared static key
• TLS -- Use SSL/TLS + certificates for authentication and key exchange

Because SSL/TLS is designed to operate over a reliable transport, OpenVPN provides a reliable transport layer on top of UDP 

一直以為OpenVPN = SSL VPN (network mode), 唉