System Management Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

PDF

System Management Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

SNMP security models and levels

Updated: June 12, 2026

Want to summarize with AI?

This section lists the SNMP security models and their supported security levels, showing the authentication and encryption mechanisms for each combination.

Simple Network Management Protocol (SNMP) uses various security models and levels to control authentication and encryption for SNMP messages. Each security model (SNMPv1, SNMPv2c, SNMPv3) supports specific security levels, which determine if messages are authenticated and/or encrypted, impacting how SNMP messages are processed and protected.

Security Levels

noAuthNoPriv: No authentication or privacy.
authNoPriv: Authentication only, no privacy.
authPriv: Authentication and privacy (encryption)

Table 1. SNMP Security Model and Level Combinations
SNMP Security Model	Level	Authentication	Encryption	What Happens
v1	noAuthNoPriv	Community string	No	Uses a community string match for authentication.
v2c	noAuthNoPriv	Community string	No	Uses a community string match for authentication.
v3	noAuthNoPriv	Username	No	Uses a username match for authentication.
v3	authNoPriv	HMAC-MD5 or HMAC-SHA	No	Provides authentication based on the HMAC (Hash-Based Messsage Authentication Code)-MD5 (Message Digest 5) algorithm or the HMAC-SHA.
v3	authPriv	HMAC-MD5 or HMAC-SHA	DES	Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides DES (Data Encryption Standard) 56-bit encryption in addition to authentication based on the CBC (Cipher Block Chaining) DES (DES-56) standard.
v3	authPriv	HMAC-MD5 or HMAC-SHA	3DES	Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides 168-bit 3DES (Triple Data Encryption Standard) level of encryption.
v3	authPriv	HMAC-MD5 or HMAC-SHA	AES	Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides 128-bit AES (Advanced Encryption Standard) level of encryption.

Use of 3DES and AES encryption standards requires that the security package (k9sec) be installed. For information on installing software packages, see Chapter Upgrading and Managing Cisco IOS XR Software in System Setup and Software Installation Guide for ASR 9000 Series Routers.

Need help?

Open a support case

(Requires a Cisco Service Contract)

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.