I have a Cisco 1921 router that I use at our head office to connect to remote offices across the country. The head office uses 172.16.3.0/24 local IP range. All of the remote locations have identical configuration with IP range 192.168.xxx.0/24. A new partner with are dealing with is also on 192.168.xxx.0/24 IP range which happens to be same range as one of the other remote offices. I understand that we need to do NAT to mask one of the locations and make it appear as if it uses a different IP range. My question is whether or not we need to do NAT on both ends or if I can accomplish this by doing it only at the head office side?
The remote offices don't need to communicate with each other. The new partner has 2-3 devices on their network that need to be able to connect to the head office, not the entire IP range.
