I have the following situation:
A clothingstore chain that has several stores, and a headquarters.
At the headquaters there is a ZyXeL USG100 with dual WAN. The stores connect through VPN (built in modem). This works fine.
They want to expand, and I have offered them a hosted exchange solution. This will be placed on our VMware Vsphere/ESX4 solution in a datacenter.
Since this is a virtual solution, I need a software solution (site-to-site) to connect to the USG at the headquarters. I can obtain singlepoint-to-site using the Greenbow VPN client, but this limits me. It will only allow me to reach the network FROM the VPN, and not TO the VPS from the network.
How do I make a site-to-site connection, using software clients? Preferently a freeware version, but this is not essential... (These are IPSec tunnels)