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macy200200
macy200200
New Member
September 6, 2020
Question

DHCP Woes - Old Fortigate 80c

  • September 6, 2020
  • 1 reply
  • 6101 views

Hey Everyone!

 

So I'm not sure what I'm doing or what's going on. I had my fortigate running fine in transparent mode but I wanted to setup a ssl vpn using port forwarding from my router so I flipped it to NAT mode.

 

My intention is to give the wan1 interface a static ip (192.168.0.6) and then use my router as a dhcp relay. My router is at 192.168.0.1. Then things connected to my FortiGate via ethernet should get an ip address from the router right? That's what I want it to do but I'm having trouble getting it to do that.

 

Soon I have a fortiap coming in the mail, then I will flip my router to bridged mode but right now I don't have internet on my devices plugged right into it unless I give them a static ip. DHCP is relaying my dns server (192.168.0.7) and that's it, no ip addresses, no subnet mask, no router.

 

Any help would be appreciated! If you need more info or something I said doesn't make sense just ask!!!

Thank you

    1 reply

    Toshi_Esumi
    SuperUser
    Toshi_Esumi
    SuperUser
    September 6, 2020

    You need to have two different subnets on WAN and LAN sides of your FGT in NAT mode. It's same as a regular router. Then likely you need to move the DHCP server from the internet router to your FGT then set a proper static route on the router to let it route to FGT for the traffice to the subnet.

     

    macy200200
    macy200200Author
    New Member
    September 6, 2020

    Yeah I think i got the static routes going. I can ping stuff from the fortigate cli and ping my dns server @ 192.168.0.7

     

    So if i put all my stuff in 192.168.1.1/255.255.255.255 I have to nat it to 192.168.0.6 since thats the wan interface static ip?

     

    I was looking stuff up and found "double nat" but I don't know how to set that up. I've honestly never had to setup a fortigate from scratch before even though I work on them all the time at work. I don't know what I'm doing lol

    Toshi_Esumi
    SuperUser
    Toshi_Esumi
    SuperUser
    September 6, 2020

    You don't have to have NAT (enable NAT on the policy) in NAT mode as long as you route the LAN to the router and router to LAN. Of course you can enable NAT on the FGT to hide LAN from the router. But it would add one unnecessary translation when you can simply route traffic through.

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