D-Link DGS-3200 Series User Manual page 35

SNMP Settings
Simple Network Management Protocol (SNMP) is an OSI Layer 7 (Application Layer) designed specifically for managing and
monitoring network devices. SNMP enables network management stations to read and modify the settings of gateways, routers,
switches and other network devices. Use SNMP to configure system features for proper operation, monitor performance and
detect potential problems in the Switch, switch group or network.
Managed devices that support SNMP include software (referred to as an agent), which runs locally on the device. A defined set of
variables (managed objects) is maintained by the SNMP agent and used to manage the device. These objects are defined in a
Management Information Base (MIB), which provides a standard presentation of the information controlled by the on-board
SNMP agent. SNMP defines both the format of the MIB specifications and the protocol used to access this information over the
network.
The Switch supports SNMP versions 1, 2c, and 3. The administrator may specify which version of SNMP to use to monitor and
control the Switch. The three versions of SNMP vary in the level of security provided between the management station and the
network device.
In SNMP v.1 and v.2, user authentication is accomplished using 'community strings', which function like passwords. The remote
user SNMP application and the Switch SNMP must use the same community string. SNMP packets from any station that has not
been authenticated are ignored (dropped).
The default community strings for the Switch used for SNMP v.1 and v.2 management access are:
•
public - Allows authorized management stations to retrieve MIB objects.
•
private - Allows authorized management stations to retrieve and modify MIB objects.
SNMP v.3 uses a more sophisticated authentication process that is separated into two parts. The first part is to maintain a list of
users and their attributes that are allowed to act as SNMP managers. The second part describes what each user on that list can do
as an SNMP manager.
The Switch allows groups of users to be listed and configured with a shared set of privileges. The SNMP version may also be set
for a listed group of SNMP managers. Thus, a group of SNMP managers can be created to view read-only information or receive
traps using SNMP v.1 while assigning a higher level of security to another group, granting read/write privileges using SNMP v.3.
Using SNMP v.3 individual users or groups of SNMP managers can be allowed to perform or be restricted from performing
specific SNMP management functions. The functions allowed or restricted are defined using the Object Identifier (OID)
associated with a specific MIB. An additional layer of security is available for SNMP v.3 in that SNMP messages may be
encrypted. To read more about how to configure SNMP v.3 settings for the Switch read the section entitled Management.
Traps
Traps are messages that alert network personnel of events that occur on the Switch. The events can be as serious as a reboot
(someone accidentally turned OFF the Switch), or less serious like a port status change. The Switch generates traps and sends
them to the trap recipient (or network manager). Typical traps include trap messages for Authentication Failure, Topology Change
and Broadcast\Multicast Storm.
MIBs
The Switch in the Management Information Base (MIB) stores management and counter information. The Switch uses the
standard MIB-II Management Information Base module. Consequently, values for MIB objects can be retrieved from any SNMP-
based network management software. In addition to the standard MIB-II, the Switch also supports its own proprietary enterprise
MIB as an extended Management Information Base. The proprietary MIB may also be retrieved by specifying the MIB Object
Identifier. MIB values can be either read-only or read-write.
DGS-3200 Series Layer 2 Gigabit Ethernet Managed Switch
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