iftop - iftop does for network usage what top(1) does for CPU usage.
vnStat - vnStat is a console-based network traffic monitor for Linux and BSD that keeps a log of network...
ntop - ntopng High-Speed Web-based Traffic Analysis and Flow Collection ntopng is the next generation version of the original ntop, a network traffic probe that monitors network usage. ntopng is based on …
darkstat - darkstat is a packet sniffer which runs as a background process, captures network traffic...
IPtraf-ng - iptraf-ng is a fork of original iptraf-3.0.0.
Zabbix - Track, record, alert and visualize performance and availability of IT resources