IKEv2

IKEv2 (Internet Key Exchange version 2) is a protocol that negotiates the keys for an IPsec-encrypted tunnel. Its standout trait is resilience on mobile devices: thanks to a feature called MOBIKE it reconnects almost instantly when you switch between Wi-Fi and cellular, so the tunnel survives changing networks. It is fast and stable and has strong native support on many operating systems, making it a common built-in VPN option. It competes with WireGuard and OpenVPN.

IKEv2 handles the handshake and authentication, while IPsec encrypts the actual data with ciphers such as AES-256. It typically runs over UDP on fixed ports, which makes it fast but easier for restrictive firewalls to block than an OpenVPN session disguised as HTTPS. Its quick reconnection and clean OS integration make it popular on phones. Like other VPN protocols it establishes an encrypted tunnel that replaces your origin IP with the server's exit IP.

s4m supports WireGuard and OpenVPN profiles. The issued profile and client routing determine the exit and which traffic follows the tunnel. s4m has selectable public exit configurations. Use the endpoint or profile issued for the protocol and location selected in your account. Consult the published privacy policy and technical descriptions for their scope; IP assignment alone does not establish a no-logs or anonymity guarantee. Related topics: VPN, WireGuard, OpenVPN, no-logs, RAM-first, VPN page.