I thought this is only associated with my routers "DNS Amplified DDoS vulnerability" on Asus RT-N56U router when using Level3 DNS "209.244.0.3 and 209.244.0.4"

I thought this is only associated with my routers "DNS Amplified DDoS vulnerability" on Asus RT-N56U router when using Level3 DNS "209.244.0.3 and 209.244.0.4" but after upgrading my firmware the issue continued. So I've changed my DNS to "8.8.8.8 and 8.8.4.4" google dns and everything started working normal for me. Good to know that this is not just me ^_^