Hello, folks! I'm author of fastnetmon, thank you for some PR for my toolkit :) I use this tool for similar type of attacks and we do analyze all traffic from uplinks ports using port mirroring. You can look at this network diagram: https://raw.githubusercontent.com/FastVPSEestiOu/fastnetmon/master/network_m... I tried to use netflow many years ago but it's not accurate enough and not so fast enough and produce big overhead on middle class network routers. It's because I wrote this tool and do every packet analyze. It can detect attack in 2 seconds max and call BGP blackhole as quick as thought. It can detect three types of attacks: 1) Speed attack for certain IP (we ban every IP which exceed 1 Gbps) 2) Packet per second attack for certain IP (we ban every IP which exceed 100 000 ppps) 3) And flow flood (very useful mode in networks with big bandwidth/pps per client) FastNetMon can handle 2-3 million of packets per second and ~20Gbps on standard i7 2600 Linux box with Intel 82599 NIC. If you need any help or suggestions you can email me directly or ask via GitHub. Thank you! -- Sincerely yours, Pavel Odintsov