I have never setup a site to site VPN before and some of the network requirements are unclear to me.
We currently pay for TLS connections through our ISP to connect 6 remote sites to our central site where all servers reside, and a single internet POP is shared. The TLS connections are slow and expensive. The goal is to instead have an internet POP at each site and utilize Site to Site VPN's for the LAN. Each remote site has IP phones and several workstations that need to access servers at the central site.
I have a SonicWALL NSA 2400 at the primary site with a static public IP.
I plan to put SonicWALL TZ215's at each remote site. Each site will have it's own internet POP (DSL) with a static IP. The DSL router will allow me to configure DMZ host, port forwarding etc. I want DHCP to be handled by the TZ215's at each remote site.
How should I configure the VPN Policies for this to function as planned?