Bi-Directional NAT or sourceNAT on LAN interface

I would like to use Peplink or MAX series as a NAT box for industrial projects. Peplink router has rugged design and support static or range NAT.
NAT Mappings works vey well. But I need an additional feature calling BiDirectional NAT for End units have not default gateway or End units whoose default gw can not be changed.
So Source NAT should be arrangable on LAN interface for me?
What do you think?
Another solution, learn default gw settings of End Units with packet capture and use Gratious ARP or Proxy ARP to catch packets destined to default gw by MAX router


Every time I have needed SNAT in the past I have just used a spare WAN port for that particular LAN segment which worked well.

Agree that SNAT would be nice to have an an option per VLAN.

Hi Matin,
Thanks for your answer.
Actually main issue is Some end Points has not default gw. Any sample you can offer?

A session initiated by SCADA server to WAN IP ( we can say Public IP ), Peplink will apply destination NAT according to a defined rule in NAT Mappings. I want Peplink also apply Source NAT when the packet egress from LAN port to End Point. In this way, End point thinks a packet is coming from End point’s subnet. So End point doesnt need a default gw to reply.

You can only do source NAT on a WAN interface currently.

Is the Peplink the default gateway for other devices on the same LAN as the device with no gateway set? If not, then you can do port forwarding to the WAN of the Peplink and forward on to an IP that is on the same (or a different) WAN.

Or you can do Layer 2 Pep VPN of course.

I am currently trying to solve this same problem. Was an acceptable solution ever found?