A lot of captive portals let you use NTP without authenticating, I guess it’s so your clock is correct for SSL or something. But if you run wireguard on your server on port 123, and connect to it, it’s tends to let you though. Plus wireguard is UDP too (like NTP) so there isn’t even a protocol mismatch. 😁
Discussion
Using the NTP port to carry VPN traffic reminds me of the best legal advice I ever heard.
If you're asked:
"Can you tell me the time?"
Always answer:
"Yes" 😂