Advantage of monitored networks
The advantage of monitored networks lies in the quick recognition of conspicuous events or even problems in the network: "Danger recognised, danger averted" is, even if not sufficient in detail, one of the fundamental ideas in automated industrial networks. Before network events, warnings or errors can be reacted to, they must first be reported to an administrator or a similar higher authority. If these messages arrive promptly and with sufficient detailed information, they can be reacted to quickly and the damage can be kept within limits. In non-monitored networks, on the other hand, the network remains eternally silent, such faults remain undetected for a long time and the damage is correspondingly high.
Technically, monitored networks have a variety of hardware and software mechanisms for detecting and signalling events and errors. In managed switches, for example, a simple link loss detection due to cable breakage or loose plug contacts is not only indicated by a small local LED on the device, as in unmanaged switches, but a warning lamp or an acoustic signal can also be triggered via an alarm relay. Furthermore, automatic notification of the IT administrators can be set up, e.g. via email or SNMP trap. Security-relevant parameters can also be set via the web interface, console port, Telnet or SNMP protocol, e.g. for the detection of third-party hardware in the network via MAC address authentication or certificate-based methods such as 802.1x. Extensive statistics on data throughput, network errors and port events help the IT administrator in both short-term troubleshooting and long-term network planning.
Areas of application
Even a brief interruption in power generation, electricity, water or gas supply systems is critical and requires continuous monitoring and a rapid response. Safety-relevant applications for traffic monitoring and control (crossings, tunnels) must also be continuously monitored. In the environment of production plants, an event may not lead to immediate danger, but perhaps to extreme costs due to failure or malfunction, so that here, too, network monitoring is practically always implemented. In building automation with the typical topics of heating, ventilation and air conditioning, the situation is perhaps a little more relaxed in terms of reaction time, but the events still have to be reported, otherwise it becomes cold and unpleasant.