Difference between Point-to-Site (P2S) VPN and Site-to-Site (S2S) VPN?

The main difference between Point-to-Site (P2S) and Site-to-Site (S2S) VPN connections lies in how they establish secure communication between networks and devices:

1. Point-to-Site (P2S) VPN:

   • Client-Centric: P2S VPNs are client-centric, meaning they allow individual devices (such as laptops, desktops, or mobile devices) to securely connect to a remote network or virtual network (VNet) in Azure.
   • Remote Access: P2S VPNs are commonly used for remote access scenarios, where individual users or devices need secure access to resources within a virtual network.
   • User Authentication: P2S VPNs typically use user-based authentication methods, such as username/password credentials or client certificates, to authenticate and establish VPN connections.
   • Dynamic IP Assignment: P2S VPNs often dynamically assign IP addresses from a specified pool to connected client devices.

2. Site-to-Site (S2S) VPN:

   • Network-Centric: S2S VPNs are network-centric, enabling entire on-premises networks or data centers to establish secure communication with Azure virtual networks (VNets) or other remote networks.
   • Inter-Network Connectivity: S2S VPNs are used to connect multiple sites or networks together, allowing seamless communication and data exchange between them.
   • Gateway-to-Gateway Communication: S2S VPNs establish encrypted tunnels between VPN gateways or routers at each site, facilitating secure communication at the network level.
   • Static IP Assignment: S2S VPNs typically use static IP addresses for VPN gateway endpoints at each site, ensuring consistent connectivity and routing.

In summary, the primary difference between Point-to-Site (P2S) and Site-to-Site (S2S) VPN connections is the scope and nature of connectivity they provide:

• P2S VPNs are focused on individual device access and remote user connectivity to specific resources within a network (such as Azure VNets).
• S2S VPNs are designed for network-to-network connectivity, linking entire on-premises networks or data centers to Azure VNets or other remote networks, enabling seamless communication between multiple sites or locations.

Both P2S and S2S VPNs play crucial roles in establishing secure and reliable connectivity in cloud environments, catering to different use cases and connectivity requirements.