Re:Cloudflare is now powering Microsoft Edge Secure Network
by gerdesj on Thursday September 28, 2023 @04:56PM
(#37695725)
... and now I come to think of it:
PPTP is generally believed to be broken so it might be "allowed" because it will be assumed that grabbing and storing the stream will be sufficient for later analysis. Then you put a OpenVPN inside the PPTP tunnel with proper, modern encryption.
... 53/tcp or udp might be worth trying too. 123/udp - ntp, 25/tcp - email! Basically try being weird - it may well work!
You can also co-exist OpenVPN on 443/tcp with a "real" web server. The usual use case for that is getting more value out of a single IP address. Put your pony fan club website up or an Ubuntu default webpage.
Another possibility is to use port knocking to open ports before the OVPN connects.