Introduction
Once again, I'm going to show my age. I remember the days when there was no standard protocol for network management. If we wanted to manage a bunch of network devices (admittedly, there were fewer pieces of hardware to manage), we would have a terminal connected to each one, or we might use telnet, and if we wanted to have a window for each device, well, Windows wasn't invented yet and there were these IBM terminals that could actually have split terminal screens. And then, after windows-based (whether Windows or Unix-based windowing systems) became available, dedicated management stations, perhaps with multiple windows for different types of information (statistics, activity, etc.) were used, but they were vendor-specific. A vendor was doing real well if the vendor had an integrated management station for its various products.
With the vendor-specific management stations, there was no standard protocol, but rather a proliferation of proprietary protocols. (You know, I wrote the previous paragraph just so I could write that alliteration! So poetic!) In an attempt to provide an integrated management station, so that the network manager would be able to work at one station, multiple applications in mutliple windows, each using a different set of protocols would be implemented. Kind of like in Figure 1.
Figure 1: Proliferation of Proprietary Protocols
SNMP was developed to solve this problem by providing a standardized network management protocol so that a common technology could be employed by network components and software, possibly from different vendors, to exchange information in a consistent manner, as represented in Figure 2. What we don't see in Figure 2 is that there might still be multiple windows, perhaps even with different applications, but at least they all use the same protocol stack to communicate with the network devices. Though the idea of one integrated network management system seems ideal, such a system is more a matter of implementation - the protocols are not in the way of achieving this.
Figure 2: One Standardized Protocol
Since the first SNMP RFCs were issued over twenty years ago, SNMP has been updated several times and has become a standard that is implemented in pretty much every networked device. Though initially intended for Internet devices, you'll find SNMP implemented in telecommunications systems and even air conditioning devices. You can also use SNMP to manage software systems. You can use SNMP to monitor, configure, and get information about devices and software using fancy graphic interfaces in expensive management systems, or with free or cheap simple management software or even command line interfaces.
Nevertheless, SNMP has not eliminated the use of other software, even telnet, in managing network devices and software systems, such as DNS, so critical to the Internet (though SSH would be more appropriate for any sensitive data). Sometimes, people want to use even "simpler" than "Simple" protocols. And, SNMP has not and never will eliminate the most useful network management application, ping, or applications like traceroute. Anyone responsible for a network knows that a whole toolbox of tools are helpful, and SNMP is one of those very helpful tools.
In the coming chapters, I'll present the SNMP architecture and protocol, and we'll use some
hands-on activities to help you understand the protocol and to make it fun. As always, we welcome your
comments. Thank you for visiting RAD University.
Debby Koren, "Dean" RAD University
