JUNOS Cookbook

Chapter 4. SNMP

Introduction

The Simple Network Management Protocol ( SNMP) is an Internet standard protocol for remotely managing routers, switches, servers, workstations, and other devices on an IP network. SNMP was first introduced in the late 1980s and is now widely supported. The first version of SNMP, Version 1 (SNMPv1; RFC 1157), defines the architecture and framework for SNMP.

SNMP Version 2 (SNMPv2) was proposed in 1993 to improve performance, manager-to-manager communications, and security. It was defined in RFCs 1155 and 1213. However, SNMPv2 was not widely accepted because the IETF did not reach consensus on the security features. A revised version, referred to as Community SNMPv2, or SNMPv2c, was later approved by the IETF ( RFCs 1902 and 3416). This version contains all the proposed SNMPv2 enhancements except for the security features, including more detailed error codes, addition of the GetBulk operation for more efficient retrieval of large amounts of data, and support for 64-bit counters. For security, this version supports community strings, which act as text-based passwords for determining how SNMP managers can access the data on SNMP agents. SNMPv2 is currently the most commonly deployed version of SNMP.

The newest version, SNMP Version 3 (SNMPv3), introduced in 1999 ( RFCs 3410 through 3418), defines stronger security features, including authentication for accessing network devices and encryption of SNMP packets. SNMPv3 uses a user-based security model (USM) ...