Chapter 1
Configuring SNMP
Table 1-1
Table 1-1
SNMP Security Models and Levels
Model
Level
SNMPv1
noAuthNoPriv
SNMPv2C
noAuthNoPriv
SNMPv3
noAuthNoPriv
SNMPv3
authNoPriv
SNMPv3
authPriv
You must configure the SNMP agent to use the SNMP version supported by the management station.
Because an agent can communicate with multiple managers, you can configure the software to support
communications using SNMPv1, SNMPv2C, or SNMPv3.
SNMP Manager Functions
The SNMP manager uses information in the MIB to perform the operations described in
Table 1-2
Operation
get-request
get-next-request
get-bulk-request
get-response
set-request
trap
1. With this operation, an SNMP manager does not need to know the exact variable name. A sequential search is performed to
2. The get-bulk command only works with SNMPv2 or later.
OL-25303-03
identifies the characteristics of the different combinations of security models and levels.
Authentication
Community string No
Community string No
Username
Message Digest 5
(MD5) or Secure
Hash Algorithm
(SHA)
MD5 or SHA
SNMP Operations
Description
Retrieves a value from a specific variable.
Retrieves a value from a variable within a table.
2
Retrieves large blocks of data, such as multiple rows in a table, that would
otherwise require the transmission of many small blocks of data.
Replies to a get-request, get-next-request, and set-request sent by an NMS.
Stores a value in a specific variable.
An unsolicited message sent by an SNMP agent to an SNMP manager when some
event has occurred.
find the needed variable from within a table.
Encryption
Result
Uses a community string match for authentication.
Uses a community string match for authentication.
No
Uses a username match for authentication.
No
Provides authentication based on the HMAC-MD5
or HMAC-SHA algorithms.
Data
Provides authentication based on the HMAC-MD5
Encryption
or HMAC-SHA algorithms.
Standard
Allows specifying the User-based Security Model
(DES) or
(USM) with these encryption algorithms:
Advanced
DES 56-bit encryption in addition to
•
Encryption
authentication based on the CBC-DES
Standard
(DES-56) standard.
(AES)
•
3DES 168-bit encryption
•
AES 128-bit, 192-bit, or 256-bit encryption
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
Understanding SNMP
Table
1-2.
1
1-3