DGS-3700-12/DGS-3700-12G Series Layer 2 Gigabit Ethernet Switch User Manual
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Simple Network Management Protocol (SNMP) is an OSI La yer 7 (Application Layer) designed specifically for
managing and monitoring network devices. SNMP enables network m anagement 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 Switc h, switch group or network.
Managed devices that support SNMP include software (referred to as an agent), which runs locally o n the device. A
defined set of variables (managed objects) is maintained by the SNMP agent and used to m anage the de vice. These
objects are defined in a Management Information Base (MIB), which provides a standard present ation of the
information controlled by the on-board SNMP agent. SNMP defines both the format of th e MIB specif ications and the
protocol used to access this information over the network.
The DGS-3700 Series supports the SNMP versions 1, 2c, and 3. The default SNMP sett ing is disabled. You must
enable SNMP. Once SNMP is enabled you can choose which version you want to use to monitor and control the
Switch. The three versions of SNMP vary in the level of security provided between the managem ent station and the
network device.
In SNMP v.1 and v.2, user authentication is accomplished using 'community strings', whic h function like passwords.
The remote user SNMP application and the Switch SNMP must use the same communit y string. SNMP pack ets 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 m anagement access are:
• public - Allows authorized management stations to retrieve MIB objects.
• private - Allows authorized management stations to retrieve and modify MIB objec ts.
SNMPv3 uses a more sophisticated authentication process that is separate d 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 s econd part describes
what each user on that list can do as an SNMP manager.
The Switch allows groups of users to be listed and conf igured with a shar ed s et of priv ileges . T he SNM P ve rs ion m ay
also be set for a listed group of SNMP managers. Thus, you m a y create a gr oup of SNM P m anager s that are a llo wed
to view read-only information or receive traps using SNMPv1 while assigning a higher level of security to another
group, granting read/write privileges using SNMPv3.
Using SNMPv3 individual users or groups of SNMP managers can be al lowed to perform or be restricted from
performing specific SNMP management functions. The functions allowed or rest ricted are defined using the Object
Identifier (OID) associated with a specific MIB. An additional layer of securit y 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 c hange. 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 managem ent an d counter information. The Switch uses
the standard MIB-II Management Information Base module. Consequently, valu es 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 MI B Object Identifier
may also retrieve the proprietary MIB. MIB values can be either read-onl y or read-write.
The DGS-3700 Series incorporates a flexible SNMP managem ent f or the s witch ing en vironm ent. SNMP m anag em ent
can be customized to suit the needs of the networks and the preferences of the network adm inistrator. U se the SN MP
V3 menus to select the SNMP version used for specific tasks.
The DGS-3700 Series supports the Simple Network Management Protocol (SNM P) versions 1, 2c, and 3. The
administrator can specify the SNMP version used to monitor and control the Switc h. The thr ee vers ions of SN MP var y
in the level of security provided between the management station and the n etwork device.
SNMP settings are configured using the menus located on the SNMP V3 folder of the web m anager. W orkstations on
the network that are allowed SNMP privileged access to the Switch can be restricted with the Management Station IP
Address window.