SNMP and SNMPv2: The Infrastructure for Network
William Stallings · 1998
The Simple Network Management Protocol is the most widely ABSTRACT used protocol for the management of IP-based networks and internets. The original version, now known as SNMPvl, is widely deployed. SNMPv2 adds functionality to the original version but does not address its security limitations; this rela- tively recent standard has not achieved much acceptance. An effort is currently underway to develop SNMPv3, which will retain the functional enhancements of SNMPv2 and add powerful privacy and authentication features. This article provides a survey of the three versions of SNMP, including a discussion of the way in which management information is in terms of managed and managing enti- ties, that SNMP is designed to address. Then we look at the protocol architecture represented and the protocol functionality he Simple Network Management Protocol T (SNMP), issued in 1988, was designed to provide an easily implemented, low-overhead foundation for multiven- dor network management of routers, servers, workstations, and other network resources. The SNMP specification: Defines a protocol for exchanging information between one or more management systems and a number of agents Provides a framework for formatting and storing manage- ment information Defines a number of general-purpose management infor- mation variables, or objects The original version of SNMP (now known as SNMPv1) rapidly became the most widely used vendor-independent net- work management scheme. However, as the protocol gained widespread use, its deficiencies became apparent. These include a lack of manager-to-manager communication, the inability to do bulk data transfer, and a lack of security. All of these deficiencies were addressed in SNMPv2, issued as a set of proposed Internet standards in 1993. SNMPv2 has not received the acceptance its designers anticipated. While the functional enhancements have been welcome, developers found the security facility for SNMPv2 too complex. Accordingly, the SNMPv2 working group was reactivated to provide a of the SNMPv2 documents. The result of this effort has been one minor success and one major failure. The minor success is the tune-up of the func- tional aspects of SNMPv2. The major failure is in the area of security. The working group was unable to resolve the issue, and two competing approaches emerged. With this tune-up, the functional portion of SNMPv2 progressed from proposed to draft Internet standard status as of 1996. Then, in 1997, work began on SNMPv3, which makes additional minor func- tional changes and incorporates a new security approach. This article will provide a survey of SNMPvl and SNMPv2, and a brief overview of SNMPv3. The article begins with a discussion of basic concepts common to all versions; these concepts define the network management framework that SNMP is designed to support. Then, the operation of SNMPvl is described. Next, the functional enhancements found in SNMPv2 are discussed. A final section introduces SNMPv3.