Site-to-Site VPN (S2S)

When you want to link networks securely, a site-to-site VPN is good place to start. It allows employees in different locations to access to securely share resources and information.

How it works

Let's say two offices in different cities, A and B wants to enable a secure communication between devices in both sites. A site-to-site VPN can connect these LANs. With each office location having a VPN Gateway, usually a router, data transmitted is encrypted at source VPN gateway and decrypted at the destination VPN gateway.

I will implement S2S when I want to:

• Connect multiple offices within the same company for secure file sharing and access to restricted services.
• Link campuses to facilitate resources sharing.
• Connect different companies working on projects.

Implementing S2S VPN

This first requires stable internet connectivity in both locations and:

• VPN-capable Routers: install a router that can handle VPN connections on each location.
• Create public IP address for each gateway.
• Configure the VPN encryption protocols, authentication methods and other relevant parameters.  

Implementing S2S in Azure

If the connection is between your on premises network and an Azure virtual network, you will need an active Azure subscription, VPN Gateway as an endpoint for the VPN connection, Local Network Gateway to represent your on-premises network. Then configure the VPN connection settings, including the shared keys and routing information.

This can be useful when you want to replicate data between on-premises and Azure for disaster recovery purposes. And when you need to ensure secure communication between your local network and Azure.