IBM 12.1(22)EA6 ユーザーズマニュアル
21-3
Cisco Systems Intelligent Gigabit Ethernet Switch Modules for the IBM BladeCenter, Software Configuration Guide
24R9746
Chapter 21 Configuring SNMP
Understanding SNMP
identifies the characteristics of the different combinations of security models and levels.
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.
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
SNMP Agent Functions
The SNMP agent responds to SNMP manager requests as follows:
•
Get a MIB variable—The SNMP agent begins this function in response to a request from the NMS.
The agent retrieves the value of the requested MIB variable and responds to the NMS with that
value.
The agent retrieves the value of the requested MIB variable and responds to the NMS with that
value.
•
Set a MIB variable—The SNMP agent begins this function in response to a message from the NMS.
The SNMP agent changes the value of the MIB variable to the value requested by the NMS.
The SNMP agent changes the value of the MIB variable to the value requested by the NMS.
Table 21-1
SNMP Security Models and Levels
Model
Level
Authentication
Encryption
Result
SNMPv1
noAuthNoPriv
Community string
No
Uses a community string match for authentication.
SNMPv2C
noAuthNoPriv
Community string
No
Uses a community string match for authentication.
SNMPv3
noAuthNoPriv
Username
No
Uses a username match for authentication.
SNMPv3
authNoPriv
MD5 or SHA
No
Provides authentication based on the HMAC-MD5
or HMAC-SHA algorithms.
or HMAC-SHA algorithms.
Table 21-2
SNMP Operations
Operation
Description
get-request
Retrieves a value from a specific variable.
get-next-request
Retrieves a value from a variable within a table.
1
1.
With this operation, an SNMP manager does not need to know the exact variable name. A sequential search is performed to
find the needed variable from within a table.
find the needed variable from within a table.
get-bulk-request
2
2.
The get-bulk command only works with SNMPv2 or later.
Retrieves large blocks of data, such as multiple rows in a table, that would
otherwise require the transmission of many small blocks of data.
otherwise require the transmission of many small blocks of data.
get-response
Replies to a get-request, get-next-request, and set-request sent by an NMS.
set-request
Stores a value in a specific variable.
trap
An unsolicited message sent by an SNMP agent to an SNMP manager when some
event has occurred.
event has occurred.