Network Monitoring Guide
As Network admin, managing network activity is critical task, there are lots of advantage of network monitoring, which helps in determining performance as well as in determining security of network.

As the name implies network monitoring is a process of overseeing a computer network using adequate software application tools. Network monitoring systems allow you to react quickly to problems in the network and help in resolving them by discovering  and analyzing the cause behind them. These systems are mostly employed by corporate firms and universities with a big network. Some people think that setting a network up and running is all that there is to it. This is wrong. A Network monitoring system (NMS) can guarantee health of your network and can be critical in building your knowledge base which will improve your troubleshooting and help with projecting future growth.

Key aspects of network monitoring

Now that I have explained the basics of network monitoring, let’s get to the actual work that it does for your network. A network monitoring system detects and reports any problems or failures of your devices or connections. It verifies if the hosts are responsive by frequently sending them messages (called watchdogs) in order to check their functionality. When the system detects slow response, failures, errors or notices unexpected behavior, it sends additional messages called alerts to the locations that you designate (e-mail, phone number etc.), in order to notify the administrators. An efficient network monitoring system will give you a clear picture of how well  network is working and does it meet the requirements for further work. Also, a good NMS will show you if you are ready to upgrade and advance your network or if you can use your existing infrastructure more efficiently without purchasing new devices. 

Network monitoring tools

Network monitoring can be divided in to two kinds, software or firmware. I will focus on the software monitoring tools in this article. One of the basic tools used in network monitoring is ping. Ping is a software tool that is available on most computers and it is used to test the reachability of a device  (host) by sending internet protocol test messages to it. For more complex information gathering you need to utilize  Simple Network Management Protocol (SNMP). This protocol is exactly what most of NMS are based on.  SNMP is used to get data like CPU temperature, CPU or memory utilisation, link state (up or down) etc. It is supported by most devices in a typical network such as routers, switchers, servers, printers, workstations etc.
There are a lot of open source tools that are innovative, cheap and some of them are even free. An example of a free and useful tool is certainly Microsoft network monitor. This tool is a packet analyser that enables you to view, capture and analyze network traffic. Another example is Fiddler, a HTTP based debugging proxy server application. If you are troubleshooting a network or applications, these type of software is what you need.

Types of network monitoring systems

There is a huge variety of network monitoring systems, with a lot of different operating regimes, and with different levels of complexity. A command line interface can be used for pinging and sending SNMP queries. The command line interface tools are useful but the learning curve is not the best and if you are a beginner, I don’t recommend them.  Luckily, there are lot of GUI (graphical user interface) tools that include detailed reporting and graphical charts. These tools are better for inexperienced users because they are a lot easier to set up and use. Another upside of these tools are the charts.

Charts can be used for presentations when you are planning network expansion for instance. Among the more complex  type of monitoring tools there are a lot of open source tools. They are usually very innovative and they are free or cheap. What more can you ask for? Well, there are a lot of different open source solutions out there, but the most common downsides are complex manual configuration (expertise needed) and lack of integration (instead of having one integrated tool you would usually need several different solutions to cover everything you want to monitor). If this is a major issue for you, then you should consider purchasing a professional NMS, they usually have trial versions available so you can test if they meet your needs – and budget.

Bottom Line

To summarize, if you want to get the best out of your network – you need to monitor it. Administrating a network without monitoring is like driving a car without speedometer or any indicators for low fuel, oil, malfunction, door ajar etc. – you can drive it, but for how long?