@Kevin_Z Swapped the port with a direct connection to a laptop and it gives the full 1000Mbps. Swapped back the LAN line to my secondary router and it gives 100Mbps Older router is a Linksys 7500....

Just got this router today to replace my older router. Set it up as a main router with wired lan connection to a secondary router. I used to be able to get 1Gbps LAN with the other older router but...