NSX edge supports site to site IPSec VPN to remote sites. You can configure multiple internal networks to connect to through the VPN tunnel. Subnets and internal networks behind the NSX edge must not have overlapping addresses. The size of the edge device determines the number of tunnels that are supported. The number of tunnels needed can be found out by using a simple equation of : “local subnets x peer subnets = number of tunnels needed”. Below is a chart taken from the NSX Administrator’s Guide outlining the number of IPSec tunnels that a edge device can handle depending on the size and also the supported algorithms.