2 WAN interfaces to 2 LAN interfaces

Question

Good day all, 
 I am running Sophos XGS3100 Firewall SFOS 18.5.2 MR-2-Build380 
 I'm trying to get lan 1 to wan 1 and lan 2 to wan 2, and in the future it will be lan 3 to wan 3.
I tried to do this via SD-WAN and Static route but after about 10 minutes gateway 2 is down and after that both lan 1 and lan 2 work through a single ip wan. 
 I also tried with SD-WAN policy route gateway is down after ten minutes and after that it doesn't work anymore. 
 
 IPs as follow: 
 WAN 1 = 28.124.156.5 
 WAN 2 = 28.124.156.6 
 (both on same gateway which is 28.124.156.1) 
 LAN 1 = 10.0.0.1 
 LAN 2 = 192.168.0.1 
 Here is what I am looking for: 
 WAN 1 --> LAN 1 
 LAN 1 --> WAN 1 
 WAN 2 --> LAN 2 
 LAN 2 --> WAN 2 
 What is working so far: 
 WAN 1 --> LAN 1 
 LAN 1 --> WAN 1 
 What is not working: 
 WAN 2 --> LAN 2 
 LAN 2 --> WAN 2 
 please help me with a solution

jprusch · Answer

Hello Eduard, 
 this won't work like that. 
 Since WAN1- IP and WAN2-IP belong to the same network, you can't expect routing to happen "somehow" different just by using to physical ports. 
 How shell routing "know" which WAN-interface to use for your internal LANs? 
 So to solve this, better go this way: you seem to have a /29 subnet form your ISP. 
 Use 28.124.156.5 /29 as the IP of Port2. Then use "Add Alias" to add 28.124.156.6 /29 to that same interface. This gives an object "Port2.0". 
 Use only this single physical port to connect to your ISP-router (your gateway). 
 The you can use NAT-rules to specify which internal LAN has which outgoing IP and vice versa, where to forward external request coming to WAN1-IP or to WAN2-IP.

2 WAN interfaces to 2 LAN interfaces

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