What Is SNMP?

Date First Published: 8th March 2022

Topic: Computer Networking

Subtopic: Internet Protocols

Article Type: Computer Terms & Definitions

Difficulty Level: 8/10

Learn more about what SNMP is in this article.

Not to be confused with SMTP.

Short for Simple Network Management Protocol, SNMP is a component of the Internet Protocol Suite used for monitoring, organising, and managing information about network devices on LANs or WANs. In other words, it is how different devices on a network share information with each other. The main purpose of SNMP is to enable devices, such as routers, servers, and printers to have a protocol for sharing information with a network management system. SNMP is an application-layer protocol and the default transport protocol that SNMP communicates with is UDP. SNMP has been around since 1988.

SNMP Commands

A number of SNP commands exist for the purpose of monitoring and exchanging management information about different network devices on LANs or WANs.

• Read - To monitor.
• Write - To configure devices and adjust device settings.
• Trap - To ‘trap’ events from the device and report them back to the monitoring system.

Security

SNMP itself is an insecure protocol due to no authentication or encryption capabilities. Because of this fact, SNMP is often used to monitor networks rather than manage them.

However, there are secure versions of the SNMP protocol that exist, such as SNMPv2 and SNMPv3. SNMPv3, the most recent version of the SNMP protocol, offers added security mechanisms, such as authentication, encryption, and access control.

SMPv3 may still be vulnerable to brute force attacks for the purpose of guessing the encryption keys if those keys are generated from weak passwords. Both supplying random evenly distributed cryptographic keys and the creation of cryptographic keys from a user-supplied password are possible with SNMPv3. The length of the hash value and the cryptographic hash function used determines the risk of guessing authentication strings from hash values communicated over the network.

Ports

The default port number of SNMP is 161. Port 162 is used when the monitoring system receives notifications.