Which VPN technology requires the installation of IPsec certificates?

L2TP, or Layer 2 Tunneling Protocol, is a VPN technology that often operates in conjunction with IPsec (Internet Protocol Security) to provide data encryption and secure communication over a network. The characteristic that makes L2TP particularly reliant on IPsec is its lack of inherent encryption capabilities; it primarily serves as a tunneling protocol that encapsulates data packets.

When using L2TP in conjunction with IPsec, IPsec provides the necessary confidentiality, authentication, and integrity of the data transmitted through the tunnel. This is achieved by requiring the installation of IPsec certificates on the devices involved. These certificates play a crucial role in establishing a secure connection, as they verify the identity of the devices and ensure that the data integrity is maintained.

In contrast, the other listed VPN technologies operate differently. SSTP (Secure Socket Tunneling Protocol) uses SSL, which is integrated for encryption without requiring separate certificates. SSL is designed to secure communications over a network, making it distinct from L2TP's reliance on IPsec. PPTP (Point-to-Point Tunneling Protocol) does not require IPsec certificates, utilizing its own method for data encapsulation and encryption. Thus, the need for IPsec certificates makes L2TP