Firewall/NAT

Hi,

I'm trying to work out if mono can have a NATted IP address/alias using a LAN address referring to a server in OPT1 (DMZ) but is accessible from the LAN?

Reason is to have the ability to gain access from a network over an IPSEC tunnel (sub-office) to the web GUI of a proxy on the OPT1 (DMZ) network?

i.e. remote office lan 10.100.100.x/24 with IPSEC to local office using LAN 10.200.200.x/24

OPT1 (DMZ) on local office uses ip address 192.168.100.x/24. Server IP would like to access is 192.168.100.50

Local LAN can access 192.168.100.50, but would like remote lan to access 10.200.200.50 which is then NATted/alias to 192.168.100.50

I've tried a 1:1 rule as well as server & inbound NAT but without success?

does anyone have any ideas on a solution?

Kind Regards
John