SNMP Foundations and Concepts8-14 Express5800/ftServer: System Administrator’s Guide for the Linux Operating SystemSNMPv3 SupportSNMPv3 support includes implementation of IETF RFCs 3410 through 3418. The thirdversion of the Simple Network Management Protocol, presented by the IETF as theInternet Standard Management Framework RFC3410, SNMPv3 incorporates elementsof SNMPv1 and SNMPv2, and shares the same basic modular architecture. Thisframework consists of four structures: a data definition language (SMIv1), amanagement information base (MIB) defining management information, a separatelydefined communication protocol, and security and administration applications andengines.Features of SNMP version 1, SNMP version 2, and SNMP version 3 are not mutuallyexclusive. IETF Best Current Practices 74 (BCP74) describes how to implement theseprotocols compatibly on networks and on internetworked environments so that objectscan be managed using the least sophisticated protocol required. In this way, networkedand internetworked objects may be managed using SNMPv1, for example, withoutbecoming obsoleted if the network is commingled into a larger network where objectsare managed using SNMPv2 or SNMPv3.This is necessary because the SNMP schema treats all networks as potentially a singlenetwork, providing for addressing every object uniquely with a single MIB. Accordingly,implementing conformant extensions to SNMP should not cause interoperabilityconflicts with existing standards-conforming SNMP implementations. In the SNMPnetwork universe, any number of SNMP servers can exist, and they can manage theobjects they know about using SNMPv1, SNMPv2, SNMPv3, and with confidence thatany SNMPv4 or subsequent protocol that may be defined will not obsolete existingSNMP servers and their managed objects.SNMP’s View of a NetworkSNMPv1 defines a simple and robust internet protocol-based communications methodfor tracking the status of and managing almost any network-interactive item that issufficiently defined as an object in a MIB.SNMP normally uses UDP protocol implemented on socket-based IP communications,but may also be implemented using TCP/IP and another IP-based protocol, and alsoon non-IP protocols such as RS-232 serial communications by spoofing an IP-basedcommunication or by piggybacking it on another transmission or transfer protocol.SNMP can also take advantage of common security enhancements implemented overIP, such as the Secure Socket Layer and other encryption, authentication, and remoteaccess technologies provided by, for example, ssh, the Openssh package.SNMPv2 expands management capabilities of SNMPv1 by providing a mechanism formore easily defining the managed objects that SNMP communicates with. SNMPrefines SNMPv2 definitions and adds important security features. Net-SNMP supportsSNMPv1, SNMPv2, and SNMPv3 protocols. Because of the simple basic structure of
