I have a number of remote sites to manage that have internet connections(based on DSL & 877 routers).
Connectivity from the remote router LANs back to HQ LAN is implemented via a standard IPSEC/GRE tunnel solution.
Provided each remote site has a unique LAN subnet then all works well.
I have no choice but to redefine all remote sites with the same LAN IP address (due to 3rd party insistance)
Therefore - I need to NAT each remote site to a unique subnet from an HQ perspective (through the GRE tunnel)
192.168.2.0/24 <--NAT via GRE--> Remote1 192.168.1.0/24
192.168.3.0/24 <--NAT via GRE--> Remote2 192.168.1.0/24
192.168.1.0/24 <--NAT via GRE--> Remote3 192.168.1.0/24
The challenge is to achieve this within one router, whilst not disturbing normal NAT action
from the remote LAN to the internet.
Please can anybody provide me with some directions on how to modify a standard IPSEC/GRE tunnel solution -- which will NAT the remote LAN address space from the local LAN address perspective?