In some situations it is not possible to set devices connected to the Cybertec up with the correct default gateway. (e.g. Device has no Gateway setting, Cybertec is being used to remotely monitor a site, etc). In this situation we are able to use Source NAT to change the source address in IP header of a packet. With Source NAT it is no longer necessary to set individual devices Default Gateway.
To Configure Source NAT Go to Firewall -> Custom NAT and Add New Custom NAT.
Set up as image below and Update.