Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have fiber coming in and being handed off via Ethernet. I am having trouble configuring the router (Fortigate 50b (recommended by one of our vendors)). It looks like it can be configured in NAT/Router and transparent modes but from how I understand the info I was given by the service provider (XO/TimeWarner) I can't determine how to set the settings.

I have two sets of IP's. "LAN Block" which contains ....

Customer LAN Block XXX.XXX.XXX.XXX//28
Customer Gateway XXX.XXX.XXX.XXX
Customer Subnet

Pretty straight forward. The IP's are public IP's provided by the service provider.

I then I have another set "wan" that only has...

Wan Block XXX.XXX.XXX.XXX/30
WAN Subnet
Network Side XXX.XXx.XXX.XXX
Customer Side XXX.XXX.XXX.XXX

Notice there is no gateway. Also the "customer lan block" are public IP's. I don't understand how to connect these two networks. In the router setup seems my only options are transparent and "NAT/ROUTER". Transparent definitely isn't what i want since in this mode I lose the ability to configure anything IP wise. I am also pretty sure i don't want NAT. I am getting spun around the axle so any help would really be appreciated.

Thanks in advance

share|improve this question

You would set the gateway to the network side for the WAN set of IPs.

Unfortunately, looking at the documentation: it doesn't appear that you can actually disable NAT when routing. I guess this is more of an "appliance" than a router. I'm not sure why this product was advised.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.