SNMP Concepts and Principles of Operation (Basic Study)

This time, we will learn more about the concept, operating principles, and where and how to use SNMP, a protocol necessary for using NMS or SMS for network management.

 

 

1. SNMP ( simple network management protocol )

 

 

▶ A protocol used to manage devices on the Internet using TCP/IP protocols.

 

Simply put, think of it as ▶ "a protocol for managing equipment in a network."

 

Generally, if you set up SNMP on a server/network equipment/SNMP-configurable equipment, the SNMP server collects information about the equipment (CPU utilization, port UP/Down, memory utilization, etc.) and uses it to display/manage programs such as NMS or SMS.

 

Collect information with MIB/OID values (I will post this part in another post later)

 

 

 

 

 

 

 

2. principles of SNMP Operation

 

 

 

 

- Management System (Manager)

 

: Use the 162/UDP port and the Agent uses the 161/UDP port.

 

 

Manager : Role of requesting information required by Agent

 

Agent : Collects information on the system where the Agent is installed or network information and delivers it to the archive manager in the form of a MIB.

 

 

 

- To communicate between the management system and the agent, at least three things must be consistent

 

 

SNMP Version : SNMP version must match between Manager and Agent.

 

Community String: Community String set to each other must match.

 

Protocol Data Unit (PDU): Message type for communication

 

 

 

 

- Manager : Systems that request information or modifications from the agent

 

- (Application or equipment in the role of requesting information that the administrator needs)

 

- Agent: Generally, it refers to network equipment that is subject to management, and the information requested by the Manager is collected and provided.

 

- MIB: Specific information and resources to be managed are called objects, and the collection of these objects is called MIB. That is, it is a database of objects that can be inquired or set by an administrator. MIBs form a tree-like structure for each object.

 

- SMI : It refers to a general structure for applying the MIB and uses the Abstract Syntax Notation (ASN.1) language, which is the official language for describing data and its properties, as in most high-level programming languages.

 

- Community String: A password used by the SNMP daemon (Manager) and the client (Agent) for authentication before exchanging data, with public or private set as the initial value.

 

 

SNMP provides Read Only (RO) and Read Write (RW) modes. If you have write permission, we recommend that you refrain from using it as much as possible, as it can cause serious security problems, such as modifying critical settings.

 

 

 

[Content that can be checked using SNMP]

 

1) Check the usage information of the system information (CPU, Memory, Disk) of the servers.

 

2) Check the traffic usage, error amount, processing speed, and interface information equipment for abnormal communication.

 

3) Network failure detection/monitoring/integrated management is possible through NMS/SMS program

 

 

 

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