Mutiple Tunnel (Route Based) VPNs to Networks with same IP Schemes (Overlapping IPs)
I have found multiple articles and questions in relation to this, but nothing to answer my question exactly.
Short summary — We have need to connect our primary firewall (TZ670) to multiple other firewalls via VPN. We have been using the Tunnel (Route) VPN for all of the ones we have so far. The hiccup is that the next 3 we have all have the same IP scheme (and cannot change them on the sites).
For Sites A and E, everything is up and functioning fine (as their respective networks are unique). The question is what is the method for building the double NAT and route from scratch for sites B, C, D?
I was able to get this working with the Sonicwall article about IPSec VPNs using the built in double NAT, but just for the sake of knowledge we wanted to know how to do this via the Tunnel interface method.
For clarity, none of the sites (A-E) need to talk to each other in any way at all. They simply need to communicate with the primary site alone.