You have several VPN protocol options:
IPsec: The industry standard for site-to-site tunnels. Works at Layer and encrypts IP packets directly.
SSL/TLS VPN: Uses HTTPS (port ) and works through most firewalls. Popular for remote access.
WireGuard: A newer protocol with simpler code and faster performance.
IPsec dominates enterprise site-to-site deployments. SSL/TLS VPNs excel for remote access because they traverse NAT and firewalls easily.