Hi.

I have been using Archer C6 Gigabit. it was working flawlessly, reaching 400 Mbps.

But suddenly one day, I had a drop in the internet speed. when i checked the router, the internet bandwidth negotiation is at 100 Mbps Full Duplex. Connecting the Ethernet wire directly to my laptop, i was able to get the same 400 Mbps speed. Similarly i connected the Ethernet wire to the LAN port, it says it connects at 1000 Mbps. So i think there is a issue with my WAN port.

My service provided checked and said that this is bcz of 100 Mbps speed in WAN(Internet) port in archer C6. 

I also changed the Internet Port negotiation speed setting in system parameters under system tools to 1000 Mbps Full duplex. It didnt work. 

Please suggest how do i rectify this.