Wireshark is the world's foremost network protocol analyzer, and is the de facto (and often de jure) standard across many industries and educational institutions.
(Wireshark was known as Ethereal until June 09, 2006)
Tcpdump prints out the headers of packets on a network interface that match the boolean expression.
Growl is a notification system for Mac OS X: it allows applications that support Growl to send you notifications.
smartmontools contains utilities that control and monitor storage devices using the Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.) system built into ATA and SCSI hard drives. This is used to check the reliability of the hard drive and to predict drive failures. It is meant to be an up-to-date replacement for the ucsc-smartsuite and smartsuite packages, and is derived from that code.
Hudson is an automated build system for a team as well as a system that monitors automated jobs (such as cron jobs)
Nagios (formerly Netsaint) is a daemon written in C that is designed to monitor networked hosts and services. It has the ability to notify contacts (via email, pager or other methods) when problems arise and are resolved. Host and service checks are performed by external "plugins", making it easy to write custom checks in your language of choice. Several CGIs are included in order to allow you to view the current and historical status via a Web browser, and a WAP interface is also provided to al...
Cacti is a complete network graphing solution designed to harness the power of RRDTool's data storage and graphing functionality. Cacti provides a fast poller, advanced graph templating, multiple data acquisition methods, and user management features out of the box. All of this is wrapped in an intuitive, easy to use interface that makes sense for LAN-sized installations up to complex networks with hundreds of devices.
Munin the monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on plug and play capabilities. After completing a installation a high number of monitoring plugins will be playing with no more effort.
Using Munin you can easily monitor the performance of your computers, networks, SANs, applications, weather measurements and whatever comes to mind. It makes it easy to determine "what's...
Webmin is a web-based interface for system administration for Unix. Using any modern web browser, you can setup user accounts, Apache, DNS, file sharing and much more. Webmin removes the need to manually edit Unix configuration files like /etc/passwd, and lets you manage a system from the console or remotely.
Webmin respects comments and configuration file order, is easy to install, includes dozens of translations, and runs on most Operating Systems.
mtr combines the functionality of the 'traceroute' and 'ping' programs in a single network diagnostic tool.
ntop [Network Top]:
ntop is a network probe that shows network usage in a way similar to what top does for processes. In interactive mode, it displays the network status on the user's terminal. In Web mode, it acts as a Web server, creating an HTML dump of the network status. It sports a NetFlow/sFlow emitter/collector, an HTTP-based client interface for creating ntop-centric monitoring applications, and RRD for persistently storing traffic statistics.
Snort® is an open source network intrusion prevention and detection system using a flexible rule-driven language, which combines the benefits of signature, protocol and anomaly based inspection methods.
With millions of downloads to date, Snort is the most widely deployed intrusion detection and prevention technology worldwide and has become the de facto standard for the industry.
monit is a utility for managing and monitoring, processes, files, directories and devices on a UNIX system. monit conducts automatic maintenance and repair and can execute meaningful causal actions in error situations.
GKrellM is a single process stack of system monitors which supports applying themes to match its appearance to your window manager, Gtk, or any other theme.
The NET-SNMP (formerly UCD-SNMP) package contains various tools relating to the Simple Network Management Protocol including an extensible agent, an SNMP library, tools to request or set information from SNMP agents, tools to generate and handle SNMP traps, a version of the unix 'netstat' command using SNMP and a Tk/perl mib browser. It was originally based on the Carnegie Mellon University SNMP implementation (version 126.96.36.199), but has been greatly enhanced, ported and fixed and barely resemble...
Privoxy is a web proxy with advanced filtering capabilities for protecting privacy, filtering web page content, managing cookies, controlling access, and removing ads, banners, pop-ups and other obnoxious junk. It is based on the Internet Junkbuster.
Tools for monitoring the hardware health of Linux systems.
Zabbix is software that monitors your servers and applications. Polling and trapping techniques are both supported. It has a simple, yet very flexible notification mechanism, and a Web interface that allows quick and easy administration. It can be used for logging, monitoring, capacity planning, availability and performance measurement, and providing the latest information to a helpdesk.
phpSysInfo is a customizable PHP script that parses various files in /proc and displays them. It will display information about system facts like Uptime, CPU, Memory, SCSI, IDE, PCI, Ethernet, Floppy, and Video. It now has full internationalization support along with customizable templates.
Zenoss is an IT infrastructure monitoring product that allows you to monitor your entire infrastructure within a single, integrated software application.Key features include: Monitors the entire stack: networks, servers, applications, services, power, environment, etc.