What Is Simple Network Management Protocol (SNMP)?

Overview Of SNMP

SNMP, an Internet standard protocol, collects and organizes information about managed devices on the IP network and modifies that information to change device behaviour.

SNMP is widely applied in network management to monitor the network. SNMP discloses the management data in the form of variables on the managed systems organized in the MIB (management information base).

These variables describe the system status and configuration and then can be queried remotely through the management applications.

As a part of the Internet Protocol Suite, SNMP is defined by the IETF-Internet Engineering Task Force. It consists of a set of network management standards, including a set of data objects, a database schema, and an application layer protocol.

Basic Components Of SNMP

There are three critical components of SNMP: Managed devices, Agent, and Network management station (NMS).

Managed Devices

A managed device or a network element is a network node that implements an SNMP interface. This interface allows unidirectional – read-only or bidirectional – read and write) approach to node-specific information.

Agent

An agent is a network-management program module that resides on a managed device.

Essential Functions Of SNMP Agent

• Acting as an agent for some non–SNMP managed network node.
• Sending an event signal to the manager.
• Collecting management information about the local environment
• Stores and retrieves the management information defined in the MIB.

Network Management Station (NMS)

The NMS performs the applications which monitor and control managed devices.

NMS offers most of the processing and memory resources necessary for network management. There may be one or more NMSs on any managed network.

Basic Commands Of SNMP

The simplicity of information exchange makes the SNMP a widely accepted protocol. The main reason is a concise set of commands, which are listed below:

• INFORM: This command is similar to a proxy-initiated TRAP. Additionally, INFORM includes confirmations from the SNMP manager when receiving the message.
• GET: This operation is a request, and the manager sends it to the managed device. Performing it can retrieve one or more values from a managed device.
• GET BULK: The GETBULK command is used to retrieve massive amounts of data from a large MIB table.
• GET NEXT: The GET NEXT command is similar to the GET command. The significant difference is that this command retrieves the value of the next OID in the MIB tree.
• RESPONSE: The command is used to carry back the value(s) or signal of actions directed by the SNMP Manager.
• SET: The manager uses this operation to modify or assign the value of the Managed device.
• TRAPS: Unlike the above commands that start from the SNMP Manager, TRAPS is initiated by the Agents. It is a signal that the Agent sents to the SNMP Manager at the time of an event.

Versions Of SNMP

SNMPv1

As the first version of the SNMP, SNMPv1 is designed in the 1980s and defined in RFCs 1155 and 1157

SNMPv2c

SNMPv2c is a revised protocol that includes enhanced SNMPv1 in terms of transport mappings, protocol packet types, MIB structure elements but the use of the existing SNMPv1 management structures.

SNMPv3

SNMPv3 defines a secure version of the SNMP. The SNMPv3 protocol facilitates the remote network monitoring configuration of SNMP entities.

While each version has matured towards rich functionality, additional emphasis is placed on the security aspects of each upgrade.

Bottom Line

The usefulness of SNMP in network management lies in the fact that it collects information about network-connected devices in a standardized way among various hardware and software types. After going through this post, you may learn insight about Simple Network Management Protocol (SNMP).