Final answer:
OpenSSL is the type of VPN that uses port 443 and is considered to be "firewall friendly".
Step-by-step explanation:
The type of VPN that uses port 443 and is considered to be "firewall friendly" is OpenSSL. OpenSSL is an open-source toolkit that implements SSL and TLS protocols and can run on port 443. It is often used for creating secure connections that can bypass firewalls since port 443 is commonly used for HTTPS traffic, which is encrypted by default.
The type of VPN that uses port 443 and is considered to be "firewall friendly" is SSL VPN. This type of VPN operates over the same port used for secure HTTPS web traffic, which makes it harder for firewalls to block. Furthermore, since port 443 is typically allowed through most firewalls for secure web browsing, SSL VPNs can bypass most firewall restrictions effortlessly.