Munin

Munin is a networked resource monitoring tool that can help analyze resource trends and "what just happened to kill our performance?" problems. It is designed to be very plug and play.

Free Open Source Mac OS X Windows Linux

Cacti

Cacti is a complete frontend to RRDTool, it stores all of the necessary information to create graphs and populate them with data in a MySQL database. The frontend is completely PHP driven.

Free Open Source Windows Linux

ntop

NTop is a hybrid layer 2 / layer 3 network monitor, that is by default it uses the layer 2 Media Access Control (MAC) addresses AND the layer 3 tcp/ip addresses. ntop is capable of associating the two, so that ip and non-ip traffic (e.g.

Free Open Source Mac OS X Windows Linux

Nethogs

NetHogs is a small 'net top' tool. Instead of breaking the traffic down per protocol or per subnet, like most tools do, it groups bandwidth by process. NetHogs does not rely on a special kernel module to be loaded.

Free Open Source Linux Xfce

iftop

iftop does for network usage what top(1) does for CPU usage. It listens to network traffic on a named interface and displays a table of current bandwidth usage by pairs of hosts.

Free Open Source Linux

vnStat

vnStat is a console-based network traffic monitor for Linux and BSD that keeps a log of network traffic for the selected interface(s). It uses the network interface statistics provided by the kernel as information source.

Free Open Source Linux BSD

wavemon

wavemon is a wireless device monitoring application that allows you to watch signal and noise levels, packet statistics, device configuration and network parameters of your wireless network hardware.

Free Open Source Linux

darkstat

darkstat is a packet sniffer which runs as a background process, captures network traffic, calculates statistics and serves them to a web browser.

Free Open Source Mac OS X Linux BSD

BandwidthD

BandwidthD tracks usage of TCP/IP network subnets and builds html files with graphs to display utilization. Charts are built by individual IPs, and by default display...

Free Open Source Linux BSD

IPtraf-ng

iptraf-ng is a fork of original iptraf-3.0.0. IPTraf-ng is a console-based network monitoring utility. IPTraf-ng gathers data like TCP connection packet and byte counts...

Free Open Source Linux

trafshow

TrafShow continuously display the information regarding packet traffic on the configured network interface that match the boolean expression. It periodically sorts and...

Free Open Source Linux

ethstatus

Ethstatus is a console-based monitoring utility for displaying statistical data of the ethernet interface on a quantity basis. It is similar to iptraf but is meant to...

Free Open Source Linux