# VPN Tunnel - [ZeroTier](https://how.router.works/remote/vpn-tunnel/zerotier.md): ZeroTier is a software-defined networking (SDN) solution that creates secure virtual networks using encrypted P2P tunnels, without requiring public IP addresses. - [Tailscale](https://how.router.works/remote/vpn-tunnel/tailscale.md): Tailscale is a VPN solution that provides seamless connectivity between devices across different networks without the need for public IP addresses or complicated firewall rules. - [Wireguard](https://how.router.works/remote/vpn-tunnel/wireguard.md): WireGuard is a modern, high-performance VPN protocol that establishes secure point-to-point connections using advanced cryptography. - [Openvpn](https://how.router.works/remote/vpn-tunnel/openvpn.md): OpenVPN uses SSL/TLS to establish secure, encrypted tunnels. It supports both site-to-site and remote access setups, offering strong security through certificate-based authentication. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://how.router.works/remote/vpn-tunnel.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.