Basic site-to-site connection using a virtual tunnel interface
This section presents a sample configuration for a connection between WEST and EAST, where a virtual tunnel interface is bound to each end of an IPsec VPN connection. When configured in this way, the VPN can be treated like any other routable interface.
When the configuration is complete, the systems are configured as shown in the following figure.
This example assumes that you have already configured a basic site-to-site connection using a preshared key between WEST and EAST, as explained in the section Basic site-to-site connection . Only the relevant changes to that configuration are presented here.