For decades, private traffic hid inside a special protocol. IPsec, OpenVPN, and WireGuard still do that: they punch an encrypted L2/L3 tunnel across the public path, then stuff TCP, UDP, SCTP, or RTP inside it. Middleboxes learned the silhouette. ESP is protocol 50. IKE is UDP/500. If those ports are blocked, the VPN is gone. … Continue reading IPSec vs MASQUE