HP Cisco Nexus 5000 Cisco Nexus 5000 Series Switch CLI Software Configuration - Page 381

Chapter 27 Configuring SNMP Information About SNMP Send feedback to [email protected] • authNoPriv-Security level that provides authentication but does not provide encryption. • authPriv-Security level that provides both authentication and encryption. Three security models are available: SNMPv1, SNMPv2c, and SNMPv3. The security model combined with the security level determine the security mechanism applied when the SNMP message is processed. User-Based Security Model Table 27-1 identifies what the combinations of security models and levels mean. Table 27-1 SNMP Security Models and Levels Model v1 v2c v3 v3 v3 Level noAuthNoPriv noAuthNoPriv noAuthNoPriv authNoPriv authPriv Authentication Encryption Community string No Community string No Username No HMAC-MD5 or No HMAC-SHA HMAC-MD5 or DES HMAC-SHA 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 Hash-Based Message Authentication Code (HMAC) Message Digest 5 (MD5) algorithm or the HMAC Secure Hash Algorithm (SHA). Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides Data Encryption Standard (DES) 56-bit encryption in addition to authentication based on the Cipher Block Chaining (CBC) DES (DES-56) standard. SNMPv3 User-Based Security Model (USM) refers to SNMP message-level security and offers the following services: • Message integrity-Ensures that messages have not been altered or destroyed in an unauthorized manner and that data sequences have not been altered to an extent greater than can occur non-maliciously. • Message origin authentication-Ensures that the claimed identity of the user on whose behalf received data was originated is confirmed. • Message confidentiality-Ensures that information is not made available or disclosed to unauthorized individuals, entities, or processes. SNMPv3 authorizes management operations only by configured users and encrypts SNMP messages. Cisco NX-OS uses two authentication protocols for SNMPv3: • HMAC-MD5-96 authentication protocol • HMAC-SHA-96 authentication protocol Cisco NX-OS uses Advanced Encryption Standard (AES) as one of the privacy protocols for SNMPv3 message encryption and conforms with RFC 3826. OL-16597-01 Cisco Nexus 5000 Series Switch CLI Software Configuration Guide 27-3