xStack
®
DGS-3120 Series Layer 2 Managed Stackable Gigabit Switch Hardware Installation Guide
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IP Address Assignment
An IP address must be assigned to each switch, which is used for communication with an SNMP network manager or
other TCP/IP application (for example BOOTP, TFTP). The Switch's default IP address is 10.90.90.90. The user may
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.
The Switch's MAC address also appears in the
Device Information
and
System Information
windows of the Web-
based management interface. The IP address for the Switch must be set before using the Web-based manager. The
Switch IP address can be automatically set using BOOTP or DHCP protocols, in which case the actual address
assigned to the Switch must be known.
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 v1 and v2, 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 v1 and v2 management access are:
•
public - Allows authorized management stations to retrieve MIB objects.
•
private - Allows authorized management stations to retrieve and modify MIB objects.
SNMP v3 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 v1 while assigning a higher level of security to another group, granting
read/write privileges using SNMP v3.
Using SNMP v3 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 v3 in that SNMP
messages may be encrypted. To read more about how to configure SNMP v3 settings for the Switch read the section
entitled Management.
