D-Link DGS-3200-16 - Switch - Stackable, Руководство пользователя

Страница: 46 / 273

xStack
®
DGS-3200 Series Layer 2 Gigabit Ethernet Managed Switch
33
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 the SNMP versions 1, 2c, and 3. 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.
SNMPv3 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 SNMPv1 while assigning a higher level of security to another group, granting read/write privi-
leges using SNMPv3.
Using SNMPv3 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 SNMPv3 in that SNMP messages may be
encrypted. To read more about how to configure SNMPv3 settings for the Switch read the next section.
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. Specifying the MIB Object Identifier may also retrieve the proprietary MIB.
MIB values can be either read-only or read-write.
The Switch incorporates a flexible SNMP management for the switching environment. SNMP management can be customized to
suit the needs of the networks and the preferences of the network administrator. Use the SNMP V3 menus to select the SNMP
version used for specific tasks.
The Switch supports the Simple Network Management Protocol (SNMP) versions 1, 2c, and 3. The administrator can specify the
SNMP version used 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.
SNMP settings are configured using the menus located on the SNMP V3 folder of the Web manager. Workstations on the network
that are allowed SNMP privileged access to the Switch can be restricted with the Management Station IP Address menu.