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New Contributor

NAT Network interface for DHCP Relay forard



On Fortigate 60F version 6.4.11, I would like to activate DHCP IP Relay on network interface.

But I would like that source network interface be natted.


Visibly these forward to IP relay don't go through Policy Firewall, so not possibility to NAT by this way.


Do you know if it's possible to do it ?


Thanks in advance




Contributor II

Hi Hervé,


The request is send by the Interface directly connected in the out interface.

I cannot understand why you have need nat? have you a schema or detailled information?


you can show a schema in this link.  (just for the schema ) 


Best regards,

New Contributor

Hello Julien,


Thank you for your information. It's exactly same situation that your schema but our internal network in my case is not routed, so not known by DHCP server. So when it send OFFER, it doesn't work of course. So, I need that IP@ relay (source address seen by DHCP server) be WAN interface address (NAT).


I saw that I didn't activate dhcp service with ip dhcp server address on WAN interface (like indicated on your doc). But even if, I think it won't work either ?





basically DHCP is udp broadcast so within a subnet it works without relaying. You only need to relay (i.e. in this case proxy) it if your dhcp server and clients are on different subnets and/or vlans/interfaces.

DHCP and DHCP relaying on a FGT are done per interface while NAT is done per Policy.

I cannot specify it anymore without more details though.


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