I would like to set up two separate networks on the RUTX10: A regular LAN on LAN ports 1 and 2, and a guest LAN with a second IP range for LAN port 3.
In the standard OpenWRT GUI, I have done this on other routers before as described in [OpenWrt Wiki] DSA Mini-Tutorial
However, I cannot find the Bridge device section in the RUTX10 web interface.
Is such a configuration possible on the RUTX10?
Alternatively, could this be done through the CLI in /etc/config/network?
For this, I would suggest following our wiki example here and creating a separate VLAN for your guest’s network. You can then attach that VLAN interface to a different firewall zone and follow the example here to manage traffic flow between the zones. You can also take a look here to see how firewall traffic rules can be used to have more granular control over the traffic.
For the WiFi Guest network, I would recommend following the configuration example here.