D-Link D DGS-3048 DGS-3048, Руководство по эксплуатации продукта

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DGS-3048 Gigabit Ethernet Switch Manual
13
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 DGS-3048 supports SNMP versions 1, 2c, and 3. You can specify which version of SNMP you want 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, you may create a group of SNMP managers that are allowed 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
Management and counter information are stored by the Switch in the Management Information Base (MIB). 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.
IP Address Assignment
Each Switch must be assigned its own IP Address, which is used for communication with an SNMP network manager or
other TCP/IP application (for example TFTP). The Switch's default IP address is 10.90.90.90. You can change the default
Switch IP address to meet the specification of your networking address scheme.
The Switch is also assigned a unique MAC address by the factory. This MAC address cannot be changed, and can be found
by entering the command "show switch" into the command line interface, as shown below.