NAT loopback on Orbi

There are two topics here: NAT Loopback and forwarding port 8090 to that server at 10.0.0.100

NAT Loopback

Any device on the 10.0.0.x LAN can reach the server directly using the IP address 10.0.0.100.

NAT Loopback will work as well:

• On the Orbi, forward port 8090 to 10.0.0.100
• Learn the WAN IP address of this Orbi, which should be 192.168.1.??
• Attempt a connection to that 192.,168.1.?? address on port 8090.
• The Orbi router will say, "oh, my. 192.168.1.?? is not out on the internet somewhere, it is me."
  It will use NAT Loopback to redirect the connection to itself, and then port forwarding will send the connection to the server.

Reaching the Server from the Internet

This can be achieved by using two Port Forwarding rules.

• On the Orbi, forward port 8090 to 10.0.0.100
• On the upstream router, forward port 8090 to the Orbi's WAN IP address (192.168.1.??)
• When a connection arrives from the internet to the upstream router's public IP address:port 8090, that router will say, "aha. connections to port 8090 go to 192.168.1.??) and forward the connection to the Orbi.
• The Orbil will say, "aha, connections to port 8090 go to 10.0.0.100" and forward the connection to the server.
• I have done this.  The key is that you must be able to set port forwarding rules on that upstream router.