(NATing-LAN means by two Ethernet ports in same system with different sub-addresses routed to each other by SNAT an DNAT rules)
Things go well when SIM card is missing but external NATing-LAN connected to Multitech MTCDT-LEU1 fails with SIM card inserted.
Having a look under mLinux through SSH, there is always a single “default gateway”, either LAN or WAN, but never both.
So messages (replies from Ping…) towards NATing-LAN might be lost in WAN when SIM card is present.
Using multiple routing tables with different routing rules would be a walk-around but it suggests the presence of multiple default gateways in the first place.
Since the network configuration is performed by application through “/var/config/db.json” instead of Linux-OS using “/etc/network/interfaces”, I am a bit lost ….
So my question : Is there a simple way to walk-around this issue ?