Cisco WS-X6K-S2-PFC2 Software Guide - Page 642

Understanding SNMP Chapter 36 Configuring SNMP Security Models and Levels A security model is an authentication strategy that is set up for a user and the group in which the user resides. A security level is the permitted level of security within a security model. A combination of a security model and a security level determines which security mechanism is employed when handling an SNMP packet. Three security models are available: SNMPv1, SNMPv2c, and SNMPv3. Table 36-2 identifies the combinations of security models and defines the levels for SNMPv1, SNMPv2c, and SNMPv3. Table 36-2 SNMP Security Levels Model Level v1 noAuthNoPriv v2c noAuthNoPriv v3 noAuthNoPriv v3 authNoPriv v3 authPriv Authentication Community String Community String Username MD5 or SHA MD5 or SHA Encryption No No No No DES What Happens Uses a community string match for authentication. Uses a community string match for authentication. Uses a username match for authentication. Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides DES 56-bit encryption in addition to authentication based on the CBC-DES (DES-56) standard. Note the following about SNMPv3 objects: - Each user belongs to a group - A group defines the access policy for a set of users - SNMP objects access an access policy for reading, writing, and creating - A group determines the list of notifications its users can receive - A group also defines the security model and security level for its users 36-4 Catalyst 6000 Family Software Configuration Guide-Releases 6.3 and 6.4 78-13315-02