Cisco WS-X6K-SUP1A-2GE-RF Software Guide - Page 645

Chapter 36 Configuring SNMP Understanding SNMPv3 Understanding SNMPv3 SNMPv3 contains all the functionality of SNMPv1 and SNMPv2c, but SNMPv3 has significant enhancements to administration and security. SNMPv3 is an interoperable standards-based protocol and provides secure access to devices by authenticating and encrypting packets over the network. The security features provided in SNMPv3 are as follows: • Message integrity-Collects data securely without being tampered with or corrupted • Authentication-Determines the message is from a valid source • Encryption-Scrambles the contents of a packet to prevent it from being seen by an unauthorized source SNMP Entity Unlike SNMPv1 and SNMPv2c, in SNMPv3 the concept of SNMP Agents and SNMP Managers no longer apply. These concepts have been combined into an SNMP entity. An SNMP entity consists of an SNMP engine and SNMP applications. An SNMP engine consists of the following four components: • Dispatcher • Message processing subsystem • Security subsystem • Access control subsystem Figure 36-1 provides an illustration of the SNMP entity. Dispatcher The dispatcher is a traffic manager that sends and receives messages. After receiving a message, the dispatcher tries to determine the version number of the message and then passes the message to the appropriate message processing model. The dispatcher is also responsible for dispatching PDUs to applications and for selecting the appropriate transports for sending messages. 78-13315-02 Catalyst 6000 Family Software Configuration Guide-Releases 6.3 and 6.4 36-7