10G RJ45 port, 10G SFP+ and 1st 2.5G RJ45 port can be configured as WAN. By default, 10G RJ45 port is primary WAN port. But after I set dual WAN, I can change primary WAN as 2.5G port and secondary WAN as USB (for fail over), then both 10G port can be connected to NAS or Switch for LAN use.