Which method does FortiGate use to secure VPN traffic?

FortiGate secures VPN traffic primarily through IPsec and SSL technologies.

IPsec (Internet Protocol Security) is a suite of protocols designed to secure Internet Protocol (IP) communications by authenticating and encrypting each IP packet in a communication session. It is commonly used for site-to-site VPNs, where two networks are securely connected over the internet.

On the other hand, SSL (Secure Sockets Layer) technology, or its successor TLS (Transport Layer Security), is used to secure the data transmitted over the internet in a more flexible environment, such as remote access VPNs. SSL/TLS provides a secure channel over an unsecured network, enabling secure web browsing and secure transmission of data between a client and a server.

Together, these technologies ensure that data transmitted over VPN connections remains confidential, unaltered, and authenticated, providing robust security measures for network communications. Thus, utilizing both IPsec and SSL technologies effectively ensures strong encryption and secure connectivity for VPN traffic, making this the correct answer to the question.