D-Link DGS-3308 Series, Руководство пользователя

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8-port Gigabit Ethernet Switch User’s Guide
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• Cold Start – This trap signifies that the Switch has been powered up and initialized such that software
settings are reconfigured and hardware systems are rebooted. A cold start is different from a factory reset in
that configuration settings saved to non-volatile RAM used to reconfigure the switch.
• Warm Start
– This trap signifies that the Switch has been rebooted, however the POST (Power On Self-Test)
is skipped.
• Authentication Failure – This trap signifies that someone has tried to logon to the switch using an invalid
SNMP community string. The Switch automatically stores the source IP address of the unauthorized user.
• New Root
– This trap indicates that the Switch has become the new root of the Spanning Tree, the trap is
sent by the switch soon after its election as the new root. This implies that upon expiration of the Topology
Change Timer the new root trap is sent out immediately after the Switch’s election as the new root.
•
Topology Change (STP)
– A Topology Change trap is sent by the Switch when any of its configured ports
transitions from the Learning state to the Forwarding state, or from the Forwarding state to the Blocking state.
The trap is not sent if a new root trap is sent for the same transition.
• New Root (STP)
– A New Root trap is sent be the switch whenever a new root port is elected within an STP
group.
• Link Up
– This trap is sent whenever the link of a port changes from link down to link up.
• Link Down – This trap is sent whenever the link of a port changes from link up to link down.
MIBs
Management and counter information are stored in 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. These MIBs may also be retrieved by
specifying the MIB’s Object-Identity (OID) at the network manager. MIB values can be either read-only or read-write.
Read-only MIBs variables can be either constants that are programmed into the Switch, or variables that change while the
Switch is in operation. Examples of read-only constants are the number of port and type of ports. Examples of read-only
variables are the statistics counters such as the number of errors that have occurred, or how many kilobytes of data have
been received and forwarded through a port.
Read-write MIBs are variables usually related to user-customized configurations. Examples of these are the Switch’s IP
Address, Spanning Tree Algorithm parameters, and port status.
If you use a third-party vendors’ SNMP software to manage the Switch, a diskette listing the Switch’s propriety enterprise
MIBs can be obtained by request. If your software provides functions to browse or modify MIBs, you can also get the MIB
values and change them (if the MIBs’ attributes permit the write operation). This process however can be quite involved,
since you must know the MIB OIDs and retrieve them one by one.
SNMP
Simple Network Management Protocol (SNMP) is an OSI layer 7 (the application layer) protocol for remotely monitoring
and configuring network devices. SNMP enables network management stations to read and modify the settings of
gateways, routers, switches, and other network devices. SNMP can be used to perform many of the same functions as a
directly connected console, or can be used within an integrated network management software package such as DView.
The Switch has a software program called an ‘agent’ that processes SNMP requests, but the user program that makes the
requests and collects the responses runs on a management station (a designated computer on the network). The SNMP
agent and the user program both use the UDP/IP protocol to exchange packets.