SNMP – Simple Network Management Protocol
Over the last decade, the development of wireless networking has accelerated the rapid expansion of computer networks. Meanwhile, network management challenges, such as managing complex networks of routers, servers, or switches, have become much more complex as a result of this expansion. This is where SNMP comes into action.
SNMP in computer networks was developed to meet the expanding need for a standard way of monitoring and controlling IP-based devices. SNMP offers its users a “simple” set of functions, allowing for remote management of these devices.
This blog will mainly focus on the SNMP protocol, its history, components, and it’s working. Let’s begin!
What is SNMP in Computer Networks?
SNMP stands for Simple Network Management Protocol. SNMP is a widely accepted and standardized application layer protocol specifically designed to exchange device management information among network devices within a TCP/IP network.
The primary function of SNMP protocol involves the gathering of statistical and configuration data related to various network devices, including computers, hubs, switches, routers, and network printers. The statistical data includes metrics such as the number of packets or frames transmitted or received per second, the rate of errors occurring per second, and so on.
It is important to note that network administrators can use the statistical and configuration data provided by SNMP to monitor the availability and performance of SNMP network devices. Administrators can also monitor the status of different SNMP versions and see the complete network with the right SNMP monitoring tool.
History of Simple Network Management Protocol
SNMP Protocol was introduced in 1988 as a successor to SGMP (Simple Gateway Monitoring Protocol) and quickly became widely adopted due to its simplicity.
Due to its ease of use, SNMPv1 was widely adopted, but due to its insufficient security protections, there is a need for better options.
In order to address the concerns raised in SNMPv1, the SNMPv2 protocol was developed in the mid-1990s. However, its new party-based security paradigm was so complicated that its adoption failed.
The third version of SNMP, i.e., SNMPv3, which was standardized in 1998, is now the industry standard for managing networks.
Before getting into the details of working on the SNMP in computer networks, let’s understand the components of SNMP.
Components of SNMP Protocol
SNMP architecture mainly consists of four components. These are:
- SNMP Manager
- SNMP Agent
- Managed Devices
SNMP Manager acts as a client and serves as the central system utilized for monitoring the SNMP network. The SNMP manager, also referred to as a network management station (NMS), is tasked with establishing communication with network devices that have implemented SNMP agents. The system operates on a host within the network.
The manager initiates inquiries with the agents, receives corresponding responses, sets variables within them, and acknowledges events communicated by them. In simple words, when the SNMP Manager initiates an inquiry, the SNMP Agent uses the Management Information Base (MIB) to send the corresponding response.
SNMP Agent acts as a server. It refers to a software process responsible for responding to SNMP queries to provide information regarding the status and statistics of a network node. The most crucial function of management is performed by SNMP agents. They are locally associated with networked devices and perform actions like collecting, storing, and transmitting monitoring data.
When queried, the designated SNMP manager receives transmitted data. SNMP software agents deployed on network devices and services establish communication with a network management system in order to transmit status information and configuration modifications.
A managed device is a node in a network that supports the SNMP and provides either one-way (read-only) or two-way (read/write) access to data about that device.
MIB (Management Information Base)
MIB acts as a database. Information exchange in an SNMP system is governed by a structure called MIB. Each SNMP agent has its own information database that contains a description of the device’s parameters that it handles. An SNMP manager is a software system that utilizes SNMP to gather data associated with capacity planning, performance management, and fault management.
The MIB serves as a shared database between the agent and the manager. Object identifiers, often known as object IDs or OIDs, are the names given to the managed objects that are included inside a MIB. The collected data in SNMP managers is stored in a MIB, which serves as a shared database between the agent and the manager.
The Object Identifier (OID) is a unique identifier for each object managed within a MIB hierarchy. Its design allows for a considerable degree of flexibility, allowing even proprietary requirements.
How does SNMP Protocol Works?
A network consists of a minimum of one computer or server and monitoring software for monitoring their activities. The managing entity is responsible for overseeing operations. The network will consist of various other devices, such as switches, workstations, routers, server racks, and printers, that require monitoring. These devices and well-known as managed devices.
SNMP messages are transmitted and received between entities commonly referred to as managers and agents. Typically, the SNMP manager is installed on the overseeing entity (managing entity) within the network, while the SNMP agents are installed on the devices being managed (managed devices).
The way messages are transferred in SNMP can be compared to the communication in the client-server model. SNMP message transfer provides both pull and push methods of data delivery.
Usually, the most common communication type uses a pull (or poll) mechanism, in which a client (such as the network management software on the managing entity) queries a server (or managed device) for information. When an event occurs, the controlled device may “speak” by sending out an SNMP message using push technology.
In terms of SNMP, a GET request originating from an SNMP manager, which acts as the client, complies with the pull model. On the other hand, an SNMP trap is “pushed out” by an SNMP agent, which functions as the server, without any preceding request.
SNMP specifies many operations for communicating between components. Below we have explained different SNMP operations in tabular form.
|GetRequest||A message sent by the manager to request the value of one or more variables from the agent.|
|GetResponse||A message sent by the agent to reply to a GetRequest with the requested values or an error indication.|
|SetRequest||A message sent by the manager to modify the value of one or more variables on the agent.|
|Trap||A message sent by the agent to notify the manager of an event or an error condition on the device.|
Advantages of Simple Network Management Protocol (SNMP)
Some of the advantages of SNMP Protocol are:
- It is simple and easy to implement.
- It supports a wide range of devices and vendors.
- It allows centralized monitoring and control of network devices.
- It provides scalability and flexibility for network management.
- It reduces network traffic and bandwidth consumption by using efficient data encoding.
Disadvantages of Simple Network Management Protocol (SNMP)
Some disadvantages of SNMP are:
- It can reduce the network bandwidth due to frequent polling and trap messages.
- It can pose security risks due to cleartext transmission and weak authentication in earlier versions.
- It can lose data packets due to unreliable UDP transport and lack of acknowledgment.
- It can generate a flood of traps in case of a major network failure or outage.
Frequently Asked Questions
Q1 – What is SNMP and its uses?
SNMP stands for Simple Network Management Protocol. It is one of the many protocols that help in managing and monitoring different types of devices that are connected over the internet.
Q2 – What are the 3 elements of SNMP?
The three main elements that play a vital role in SNMP architecture. These are:
- SNMP Manager
- SNMP Agent
- Managed Devices
Q3 – What is the advantage of SNMP?
SNMP has various advantages; one of the main advantages of SNMP is that it helps in managing network devices that don’t have OS (operating system).
Q4 – What is the principle of SNMP?
It is a standard protocol that allows network devices to communicate and exchange information via sending messages known as PDUs with a central management system.
SNMP in computer networks is critical for networking management and monitoring. This blog has discussed SNMP, its working, architecture, advantages, and disadvantages. We have also covered the different operations that are carried out between the agent and the manager for a better understanding of the working of SNMP protocol. Learn more about SNMP in Computer Networks by joining a CCNA Online Course.