I have an RT-N66U that has started slowing way down and the fix is always to switch from the 2.4 to the 5GHz network or vice versa. As soon as I switch networks, it's back to normal. I've left pings running to external IP addresses and they slow down to 800-1100ms. At the same time, pinging either the public or private IP of the N66U results in sub 20ms pings. It doesn't matter if my computer is right next to the router and this happens to multiple computers.
Does this mean it may not be the Asus router but an issue with my cable modem instead? When I switch networks, I keep the exact same private IP address but the speed is right back to where it should be until it starts to happen again. I've looked over the system log but there's nothing displayed when this happens. I've also reset the NVRAM and manually configured the router from scratch and it's running the latest Asus firmware.
Does this mean it may not be the Asus router but an issue with my cable modem instead? When I switch networks, I keep the exact same private IP address but the speed is right back to where it should be until it starts to happen again. I've looked over the system log but there's nothing displayed when this happens. I've also reset the NVRAM and manually configured the router from scratch and it's running the latest Asus firmware.