I've been trying to figure out a particular configuration that will involve the use of both NAT and SAT - I've read so many docs/faqs/examples etc that I'm now more confused than when I started!!
The IP layout is as follows:
- I have 3 public IP's that I can use, for now lets call these 192.168.200.1, 192.168.200.2 and 192.168.200.3 (obviously these are not the actual real world IP's)
- There is a https server in the DMZ, it's IP is 172.16.100.2 [SAT]
- There is also a server on the LAN which can make connections out, and requires it's own IP. This server can not sit on the DMZ. This is on an internal IP of 10.4.3.2 [SAT]
- All other machines on the LAN can also make outbound connections, but can share the same public IP [NAT]
What I am trying to achieve is the following:
- Any machine on the LAN (other than the one specific server) can make requests out to the internet. They will be somewhere/anywhere in the range of 10.4.3.3 to 10.4.3.100 and need to make their connections to the outside world as if coming from the first public IP (192.168.200.1). Responses to outbound connections are to be allowed, but no initial connections from the outside.
- The server on the LAN (10.4.3.2) is to be allowed to make outbound connections, and these must appear as if from the second public IP (192.168.200.2). Again responses to outbound connections are to be allowed, but no initial connections from outside.
- The server on the DMZ (172.16.100.2) is allowed to be connected via https for requests made to the third public IP (192.168.200.3). It can also make connections out (which must also appear as coming from the third public IP) which must allow the responses back in, but the only connection allowed to be initiated from outside is to the https service.
OK, as you can see I'm finding it hard to even explain what I'm trying to do, let alone figure out how to do it. I've been looking into ARP settings, SAT options etc etc and just can't seem to see a way of doing this. Got to the stage where I'm loosing the ability to read....
Can anyone give any advice on how do to this, assuming I have given you enough details for you to see what I am trying to do.
Thanks.