It depends on the firewall. For example, a Palo Alto can match by application and do SSL decryption in where the firewall acts as a MITM. A locked down enviro

It depends on the firewall. For example, a Palo Alto can match by application and do SSL decryption in where the firewall acts as a MITM. A locked down environment would likely only allow SSL on TCP/443, and block UDP/443 to deny QUIC. An application that breaks RFC would likely be blocked. It’s also common to block unknown TCP/UDP applications.