WEB Manager User Guide
Appendix A- Useful Information
Version
2.1 51 March
2003
7 Useful
Information
7.1 SNMP
Background
The Simple Network Management Protocol (SNMP) is a standard that allows
management data on different network devices to be read and monitored, as
well as controlled by an application. PowerDsine PowerView monitors and
controls SNMP objects on any device implementing an SNMP agent.
7.2 SNMP
Protocol
SNMP is based on the manager/agent model. SNMP is referred to as "simple"
because the agent requires minimal software. Most of the processing power
and the data storage resides on the management system, while a
complementary subset of those functions resides in the managed system.
To achieve its goal of being simple, SNMP includes a limited set of
management commands and responses. The management system issues
Get
,
GetNext
and
Set
messages to retrieve single or multiple object variables
or to establish the value of a single variable. The managed agent sends a
response message to complete the
Get
,
GetNext
or
Set
. The managed agent
also sends an event notification, called a
trap
to the management system to
identify the occurrence of conditions, such as a threshold that exceeds a
predetermined value. In short there are only five basic operations:
get
(retrieve operation)
get next
(traversal operation)
get response (indicative operation)
set
(alter operation)
trap
(asynchronous trap operation).
7.3 Outline of the SNMP protocol
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Each SNMP managed object belongs to a community
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NMS station may belong to multiple communities
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A community is defined by a community name, that is an OctetString with
0 to 255 octets in length.
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Each SNMP message consists of three components:
#
version number
#
community name
#
data - a sequence of PDUs associated with the request.
