10 個免費的網絡監控工具
互聯網的飛速發展，互聯網的使用越來越普遍，網絡和互聯網不僅成為企業內部的溝通橋梁，也是企業和外部進行各類業務往來的重要管道。
網絡監控軟件定義：指針對局域網內的計算機進行監視和控制，針對內部的電腦上互聯網活動（上網監控）以及非上網相關的內部行為與資產等過程管理（內 網監控；所以包含了上網監控（上網行為監視和控制、上網行為安全審計）和內網監控（內網行為監視、控制、軟硬件資產管理、數據與信息安全），有些還增加了 數據安全的透明加密軟件部署。
1. Monit
Monit 是一個Linux/UNIX系統上開源的進程、文件、目錄和文件系統監控和管理工具，可自動維護和修復一些錯誤的情況。
Monit is a great tool that not only supervises your server, but also tries to solve the issues by taking predetermine actions for specific situations. For instance, when your database server crashes, this tool has the ability of automatically restarting the service if this is the action that you wish to take (which usually is).
If you need to supervise more than one server, then you can utilize M/Monit, which is an extended version of Monit that allows monitoring multiple machines.
Its iPhone app is also available so that you can easily check on your network from anywhere.
2. Ganglia
Ganglia是一個跨平臺可擴展的，高 性能計算系統下的分布式監控系統，如集群和網格。它是基于分層設計，它使用廣泛的技術，如XML數據代表，便攜數據傳輸，RRDtool用于數據存儲和可 視化。它利用精心設計的數據結構和算法實現每節點間并發非常低的。它已移植到廣泛的操作系統和處理器架構上，目前在世界各地成千上萬的集群正在使用。它已 被用來連結大學校園和世界各地，可以處理2000節點的規模。
Ganglia is a cool tool that will let you see how the whole cluster of machines is doing all at once. If you are working with a server cluster then this is the ultimate tool for you, but it might prove to be overkill for single-machine set-ups.
3. Munin
This tool supervises monitors and graphs system performance metrics. It has the ability of automatically producing daily/weekly/monthly/yearly performance graphs and reports of various significant metrics. It can monitor core system resources, like memory, disk space, CPU usage, server apps like MySQL, Apache, and Squid.
One of the best thing about this tool is that it can be extended quite easily. simply write a few lines of code, and you can create a plugin to supervise almost anything. We know that Munin is very easily extendable, so it can also prove to be a great choice for graphing things that are not even related to server performance, for instance, the number of user signups or website popularity etc.
4. Cacti
Cacti 在英文中的意思是仙人掌的意思，Cacti是一套基于PHP,MySQL,SNMP及RRDTool開發的網絡流量監測圖形分析工具。它通過 snmpget來獲取數據，使用 RRDtool繪畫圖形，而且你完全可以不需要了解RRDtool復雜的參數。它提供了非常強大的數據和用戶管理功能，可以指定每一個用戶能查看樹狀結 構、host以及任何一張圖，還可以與LDAP結合進行用戶驗證，同時也能自己增加模板，功能非常強大完善。
This one is quite like Munin. But what makes Cacti different is the fact that it lets you resize your graphs and see data for an arbitrary range. While Munin only provides fixed daily, weekly, monthly and yearly graphs (unless you have created a custom extension), Cacti allows viewing your data in any way you like: last 2 hours, last 4 days, last 6 months, out of the box. You even have the ability of visually selecting and zooming into regions on your graphs.
5. Nagios
Nagios是一個監視系統運行狀態和網絡信息的監視系統。Nagios能監視所指定的本地或遠程主機以及服務，同時提供異常通知功能等
Nagios可運行在Linux/Unix平臺之上，同時提供一個可選的基于瀏覽器的WEB界面以方便系統管理人員查看網絡狀態，各種系統問題，以及日志等等。
This tool’s website says that it is “the industry standard in IT infrastructure monitoring”. Although this tool is a bit complicated to install and configure, but its all worth the pain as it boasts a plethora of awesome features. Nagios definitely stands out from all the rest of its competitor and is geared for the experienced IT network administrator. Nagios has the ability to monitor multiple hosts and also sends out alerts through email, pager (if you still use it!) or SMS/text messaging. Similar to Monit, it can also be configured to automatically respond to issues.
6. Zabbix
zabbix是一個基于WEB界面的提供分布式系統監視以及網絡監視功能的企業級的開源解決方案。
Zabbix is a great tool with a plethora of different features. It has amazing visualization support including user-defined views, zooming, and mapping. It has the ability of sending out alerts through email, SMS or instant message. It even provides audible alerts, that can prove to be quite helpful when you are near the monitoring machine.
7. Observium
Observium 是一個可自動發現網絡中的思科設備和 Linux系統的網絡監控工具，而是包括了主要的網絡硬件和操作系統的廣泛支持。 Observium發展出來的一種輕松缺乏使用NMSes。其目的是提供一個更加通航接口的健康和你的網絡性能。它的設計目標包括收集盡可能就設備多的歷 史資料，是完全與很少或無需人工干預的自動發現，并有一個非常直觀的界面。
This tool is geared towards Linux, BSD and Cisco networks. It boasts an auto discovery feature that finds the networks that you are most probably interested in monitoring. It provides detailed graphs, and has the ability of being set up with Nagios to provide alerts. It can also be integrated well with Collectd, which is reviewed below, for a more rich interface.
8. Zenoss
Zenoss Core是開源企業級IT管理軟件-是智能監控軟件，他允許IT管理員依靠單一的WEB控制臺來監控網絡架構的狀態和健康度。Zenoss Core同時也是開源的網絡與系統管理軟件。
It is an open source version of the commercial server monitoring tool called Zenoss Enterprise. It was written in Python. It supports the Nagios plugin format, so various Nagios plugins can be utilized in Zenoss. One of the most amazing thing about this tool is that it has a powerful but handy user interface.
9. Collectd
collectd是一個守護(daemon)進程，用來收集系統性能和提供各種存儲方式來存儲不同值的機制。比如以RRD 文件形式。
當系統運行和存儲信息的時候，Collectd會周期性統計系統的相關統計信息。那些信息可以用來找到當前系統性能瓶頸。（如作為性能分析 performance analysis）和預測系統未來的load（如能力部署capacity planning）.如果你需要美觀的圖形來顯示您的數據，并且已經厭煩了內部解決方案，恭喜您，你找到了正確的地方。
This tool is like Munin and Cacti in that it focuses on graphing system metrics. Its speciality is that it has been designed specifically for performance and portability; which means that is it great for rugged systems, low-end systems, and embedded systems. Collectd can collect data every 10 seconds without interfering with your server processes, giving you really high-resolution statistics. You can even write extensions for it in C, Perl or Java.
10. Argus
Argus 是一個網絡連接監控器，可以利用它來定制監控網絡中符合某種條件的計算機，例如網絡空閑、斷開等。
This is a great tool that focuses on monitoring network services. It supports IPv4 and IPv6. It has an awesome alert escalation process: if the alert has been sent but the problem is still not resolved within a fixed time, another alert will be sent out to someone else.
來自：http://bloggerspath.com/the-most-popular-asp-net-cms-downloads/