User-Based Security Model - Cisco Nexus 7000 Series Configuration Manual

Configuring SNMP
Model
v3
v3

User-Based Security Model

The 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 nonmaliciously.
• 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.
Level Authentication
authNoPriv HMAC-MD5 or
HMAC-SHA
authPriv HMAC-MD5 or
HMAC-SHA
Cisco Nexus 7000 Series NX-OS System Management Configuration Guide
Encryption What Happens
No Provides
authentication based
on the Hash-Based
Message
Authentication Code
(HMAC) Message
Digest 5 (MD5)
algorithm or the
HMAC Secure Hash
Algorithm (SHA).
DES 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
177