Best Practice Site-to-Site VPN IPsec IKEv2

Quick Answer

IPsec with IKEv2 is considered best practice for site-to-site VPNs because it combines strong, well-established security properties with practical operational advantages that matter for a connection meant to stay up persistently between two fixed locations. IPsec itself handles the actual protection of traffic between the two endpoints, providing authentication, encryption, and integrity checking so that data crossing the internet between the sites can't be read, forged, or tampered with in transit. IKEv2 is the protocol responsible for negotiating and managing the security associations that IPsec relies on, and it improves meaningfully on its predecessor, IKEv1: it supports faster rekeying, which reduces the window of exposure as cryptographic material is periodically refreshed, it includes built-in mobility support so a connection can survive an endpoint's network path changing, and it has stronger built-in resistance to denial-of-service attacks during the negotiation process. For a site-to-site connection specifically, as opposed to a remote-access VPN for individual traveling users, these characteristics matter because the tunnel needs to remain stable and secure over long periods with minimal manual intervention. When a question asks about the recommended protocol for site-to-site VPNs specifically, IPsec with IKEv2 is the modern, standard answer, distinguished from older or less robust key-exchange alternatives by its efficiency and resilience.