Wifi slow on Airport Extreme when connecting ethernet devices
I have an AirPort Extreme 802.11n (4th Generation) as router (firmware 7.6.4). It's connected to 100mbit/s fiber.
Wifi connection is great. But if I connect my Mac Pro with an ethernet cable the wifi connection gets really bad on my Macbook Pro. Streaming video is almost impossible. If I connect my Time Capsule via ethernet the internet connection gets unusable on all devices regardless wifi/ethernet. Websites take minutes to load!
Settings are DHCP & NAT (200 ip addresses), wifi is a WPA2 Personal. I have no idea where to start.
Has anyone had a similar issue?