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Rockwell Automation Publication 1783-UM007I-EN-P - December 2017 259
Configure Switch Features Chapter 3
Simple Network
Management Protocol
(SNMP) The switch supports SNMP versions 1, 2C, and 3. SNMP enables the switch to
be remotely managed through other network management software. This
feature is disabled by default.
SNMP is based on three concepts:
•
SNMP managers (client software)
•
SNMP agents (network devices)
•
Management Information Base (MIB)
Refer to Supported MIBs on page 260 for the MIBs supported on the switch.
The SNMP manager runs SNMP management software. Network devices to
be managed, such as bridges, routers, servers, and workstations, have an agent
software module. The agent provides access to a local MIB of objects that
reflects the resources and activity of the device. The agent also responds to
manager commands to retrieve values from the MIB and to set values in the
MIB. The agent and the MIB are on the switch. To configure SNMP on the
switch, you define the relationship between the manager and the agent.
Both SNMPv1 and v2C use a community-based form of security. SNMP
managers can access the agent MIB through passwords referred to as
community strings. SNMPv1 and v2C are used for network monitoring
without network control.
SNMPv3 provides network monitoring and control. It provides secure access
to devices by a combination of authenticating and encrypting packets over the
network. The security model that is used by SNMPv3 is an authentication
strategy that is set up for a user and user group. A security level is the permitted
level of security within a security model. A combination of a security model
and a security level determines which security mechanism is used for an SNMP
packet.
The following are guidelines for SNMPv3 objects:
•
Each user belongs to a group.
•
A group defines the access policy for a set of users.
•
An access policy defines which SNMP objects can be accessed for
reading, writing, and creating.
•
A group determines the list of notifications that its users can receive.
•
A group also defines the security model and security level for its users.
•
An SNMP view is a list of MIBs that a group can access.
•
Data can be securely collected from SNMP devices without fear of the
data being tampered with or corrupted.
•
Confidential information, for example, SNMP Set command packets
that change a router configuration, can be encrypted to help prevent the
contents from being exposed on the network.
IMPORTANT SNMPv.3 is available only in cryptographic switch firmware.