VIP and nat

[TomerDi1987]

I have 3 WAN interface, I configure VIP Port 80 to internal server:

WAN1(isp1) -> port 80 to 192.168.17.1 port 80

WAN2(isp2) -> port 80 to 192.168.17.1 port 80

WAN3(isp3) -> port 80 to 192.168.17.1 port 80

My default route point to  WAN2 (ISP2)

When the client go to the server by the VIP I want:

traffic comes from any source to WAN1 will go back to the source from WAN1

traffic comes from any source to WAN2 will go back to the source from WAN2

traffic comes from any source to WAN3 will go back to the source from WAN3

any Idea how to do that ?

Is enable NAT on the policy will make sure that traffic will return from the same interface that arrived ?

[Toshi_Esumi]

You need three default routes to all of them. As long as routes are there FGT should route return traffic back to where it's initiated.

[OneOfUs]

To add on to what Toshi stated, you may want to look at using ECMP:

https://kb.fortinet.com/kb/viewContent.do?externalId=100137