SNMP Basic Function



SNMP stands for Simple Network Management Protocol. It was developed as part of several Internet Protocols. Today it is used extensively to oversee devices connected to various types of network management systems.

How SNMP Works

The following is an example of how SNMP operates. Assume that there is a network management system (NMS), and it has several “mini networks” or “network elements” attached to it. There is a constant stream of data moving back and forth which must be supervised by the main network system.

To make this process easy, an SNMP component (often called an SNMP agent) is installed in each of these network elements. Each SNMP agent has different tasks, but what they all basically do is provide feedback information on each network element to the main network.

The information that is processed includes relaying facts about available system resources, memory, programs running, etc. All of these are relayed by way of SNMP to the network or system in charge. All the major operating systems, from Windows to UNIX, can be configured to have SNMP agents installed.

SNMP Versions

From its inception in 1988, SNMP has undergone several modifications. While most network systems avail of SNMPv1 and SNMPv2, (for community security), some other upgrades like SNMPv2u and SNMPv2 enable security for users.

Typical Components of an SNMP

Depending on the network, an SNMP could have several components, but even the simplest have the following:

Managed Device or Network Elements

This is the element that holds the SNMP agent. The information contained here is what is relayed back to the network management system. Parts that can constitute an element range from printers to hubs to routers; IP telephones, hosts, servers, bridges and switches are also part of the elements.

This is the program that is in the network element that makes the transfer of data to the network management system possible. Its main purpose is to monitor the different aspects and variables in each network element.

Network Management System

This is where the info is sent to, and what may be called the “control center”. There is usually only one NMS however in huge networks there could be several running at once.

Examples of SNMP Messages

There are several types of SNMP messages that can be released or created by the main network or any of its sub elements.

SNMP TRAP: this is a typical message sent to the main network system by one of the elements it is supervising in case it fails to function properly or a hardware failure occurs.

SNMP GET is used by the main network to get data from one of the other network elements. To alter some data, SNMP SET is utilized while SNMP MIB is used to modify the variables in both hardware and software.