SNMP – Simple Network Management Protocol

SNMP is short for Simple Network Management Protocol. It is a platform for managing internet-connected devices. It offers a collection of functions for monitoring and managing the internet.

Concept of SNMP:

Manager and agent are the two components of SNMP. The manager is a host that manages and controls a group of agents such as routers. It is an application layer protocol that allows a few management stations to manage a group of agents.

The application-level protocol can monitor devices produced by many manufacturers and placed on various physical networks. It is utilised in a heterogeneous network composed of several LANs and WANs linked by routers or gateways.

What are Managers and Agents in SNMP?

A host that runs the SNMP client programme is referred to as a manager, whereas a router running the SNMP server software is referred to as an agent. The internet is managed by easy contact between a manager and an agent.

The agent is responsible for storing information in a database, whereas the manager is responsible for accessing the values in the database. For example, a router can record relevant information such as the number of packets received and sent, and the management can compare these data to determine whether or not the router is congested.

Agents can also help with the management process. The agent’s server software examines the environment; if something goes wrong, the agent sends a warning message to the manager.

Basic Ideas/Rules of SNMP:

A manager verifies the agent by asking for information that indicates the agent’s conduct. It can also compel an agent to execute a certain task by resetting settings in the agent database. An agent also helps the management process by alerting the manager to an unexpected state.

Components of Management in Networks:

Management is accomplished not just via the use of the SNMP protocol, but also through the use of additional protocols that can collaborate with the SNMP protocol. It is accomplished through the usage of the other two protocols: SMI (Structure of management information) and MIB (Management Information Base) (management information base).

SMI, MIB, and SNMP are used for management. All three protocols, including abstract syntax notation 1 (ASN.1) and fundamental encoding principles, are used (BER).

1. Structure of Management Information (SMI):

SMI is an important network management component. Its primary role is to specify the types of data that may be kept in an object and to demonstrate how to encode the data for transmission across a network.

2. Management Information Base (MIB):

The MIB (Management information base) is a second network management component.

Each agent has its own MIB, which contains a list of all the things that the manager may control. MIB is divided into eight categories: system, interface, address translation, ip, icmp, tcp, udp, and egp. These groups are contained within the mib object.

3. Simple Network Management Protocol (SNMP):

SNMP can send the following 5 messages:

a. GetRequest:

The GetRequest message is delivered from a manager (client) to an agent (server) to get the value of a variable.

b. GetNextRequest:

The GetNextRequest message is delivered from the manager to the agent in order to get the value of a variable. This message type is used to obtain the values of table entries. If the manager does not know the indices of the entries, the values cannot be retrieved. In these cases, the GetNextRequest message is used to define an object.

c. GetResponse:

In response to the GetRequest and GetNextRequest messages, an agent sends the GetResponse message to the manager. This message includes the value of a variable that the manager requested.

d. SetRequest:

A manager sends the SetRequest message to the agent to set a value in a variable.

e. Trap:

A Trap message is sent to the manager by an agent to report an occurrence. For example, if the agent is restarted, it notifies the management and transmits the time of the reboot.

Advantages of SNMP:

1. SNMP is the most well-known network management protocol, thus it is used quite widely.

2. This protocol is not affected by the operating system or the programming language.

3. This protocol’s functional design is portable.

4. The SNMP protocol is essentially a core set of activities that are consistent across all monitored devices. As a result, SNMP allows for extensibility.

5. It is a simple protocol.

6. This protocol enables access to dispersed management.

Disadvantages of SNMP:

1. The network’s bandwidth is reduced as a result of this protocol.

2. Some of the most serious security problems include access control, authentication, and data privacy.

3. SNMP works with data that is neither detailed nor well structured.

Summary:

In this article, we looked at the inner workings of the Simple Network Management Protocol (SNMP) and also the various components involved in the functioning of this protocol. We also looked at the various advantages and disadvantages of this protocol.