Zabbix - Track, record, alert and visualize performance and availability of IT resources
SolarWinds NPM - Advanced network monitoring for on-premises, hybrid, and cloud. Download a FREE 30-day trial of SolarWinds Network Performance Monitor (NPM) today!
nfsen-ng - nfsen-ng aims to be an in-place replacement for the ageing nfsen.
SolarWinds Netflow Traffic Analyzer - Identify how bandwidth is being used with NetFlow Traffic Analyzer for SolarWinds Network Performance Monitor. Download free 30-day analyzer software trial!
FastNetMon - FastNetMon is a very fast DDoS analyzer with sflow/netflow/mirror support.
Progress WhatsUp Gold - Progress WhatsUp Gold is an all-in-one Network monitoring utility that now offers even more features and functionality to help you monitor your servers, network, and IP address.