FriendlyElec launched NanoPi R1S router with two Ethernet ports based on either Allwinner H3 or H5 processor coupled with 512MB RAM last November. Both ports are "Gigabit" Ethernet port, but one is implemented via a USB 2.0 to Ethernet controller with a maximum bandwidth of around 330 Mbps.
If you'd like to get two Gigabit Ethernet reaching close to 1 Gbps each, and your target application would benefit from a bit more memory, the company is now working on NanoPi R2S based on Rockchip RK3328 processor with 1GB DDR4 memory, one Ethernet port using the GMAC from the chip,