Network monitoring is a key component of any networked system. This monitoring allows technicians to determine the reliability of the network and prevent large crashes by fixing or replacing downed components. In certain cases, careful monitoring can point out problems in the network before they become large enough to affect network users. Careful network monitoring can also affect the percentage of downtime that is planned compared to unplanned, thus improving general network availability statistics.
Most network monitoring programs send periodic requests to different servers in the system and measure the response times. These response times are typically derived from port and service ‘pinging’ which tells the system administrator how quickly the servers speak to one another, or indeed, if they are offline.
Good network monitoring applications will also monitor the amount of data sent and the bandwidth used. This allows the system administrator to monitor and control network bandwidth usage by individual servers and systems. Of course, it’s also a great way to catch broken components and security issues.
This is not the only thing you can do while monitoring a network. Network tomography helps with the design of useful networked systems. Tomography uses the ends points of data sent through the internet in order to figure out the path that information takes to get from point A to point B. Using this information, it is possible for system administrators and computer scientists to design better computer networks, and better ways to connect servers. The idea is to reduce the distance and time spent in any server request through design. Thus improving the efficiency of your network, and improving usage of hardware.
Although it is not as common as using network monitoring systems to check the uptime of a server, network tomography is a growing field, and can be used as in a similar manner to regular monitoring to figure out where network delays occur. Tomography can also be used to figure out which links are naturally more lossy than others. This makes it possible to fix those links in the network and speed up network response times and reliability.
Ideally, any network monitoring would include alerts for failed server requests. Depending on the type of network monitoring system, these alerts can take the form of a visual/audio alarm or messages sent to the system administrator’s SMS, instant messenger, email or voice mail.
Features to look for in network monitoring systems:
How does it send alerts? Make sure that the system will send you alerts in a way that will definitely get to you. The system should be capable of being set to send more than one alert at a time. That way, no matter where you are, you will always be able to know when the network goes down. This will minimize unplanned downtime.
High ratings and/or good reviews. One of the best network monitoring programs on the market right now is ServersCheck. It has won awards for best network product at the ITpro Expo in October of 2008 and continues to release innovative new products and services in its network monitoring range. This is due to the ease of use, reliability, and the many different ways that the system can send alerts. Whether you prefer to get phone calls, emails or instant messages, ServersCheck will alert you to system downtime.
Free trial. It is a good idea to look for network monitoring systems that allow you a free trial. ServersCheck, for example, gives a free 21 day trial so that you can test out the program features yourself. Make sure that the free trial is at least three weeks – otherwise, you might not have enough time to test all of the program features. While you are testing the program, you should make sure that you run some tests to see whether or not the monitoring software is working properly.
Other features. Many of the network monitoring options on the market will only monitor the network, or are otherwise limited in their features. If you are only looking for a tool to monitor your bandwidth use, then this may not be a major problem. However, there are other options available that will give you many more features for your money. If you are planning on running a server for a long period of time, then you should look into a program that will monitor much more than uptime and bandwidth.
There are a few monitoring options that do not require downloads – these monitors can be accessed online. These options are often open source and free, however the features are usually limited.
Once again, ServersCheck can deliver – it promises to monitor with more than 60 different checks ranging from the standard network monitoring all the way to environmental monitors. This way you can keep an eye on your network up time as well as the physical environment around the servers. Why go with a type of network monitoring system that doesn’t also monitor server room temperature, humidity and under-floor flooding?
Overall, network monitoring has become a much more precise science in recent years. It is possible to find applications, software and hardware monitors to check almost any server room conditions. Although network tomography can help to study networked servers, your best bet will always be network-specific options. With proper network monitoring, you can keep your network running smoothly – and get immediate alerts when any servers go down.