Software User Manual Extract, Edited Version
Our SNMP agent builder
iwas designed and implemented
using object-oriented methodology and
design patterns. One of its the design goals
minimize the effort s expended in of
building SNMP snmp agents.
Most of the hard work s are has already
been done in designing the base classes and
is hidden from the users. For example,
the developer does not have to worry about
the complexities such as
SNMPv3 engine auto-discovery, encoding and decoding, dynamic row creation and deletion,
and inter-table indexing. etc, a All
this ose functionality and logic
areis already built into the core library.
All versions of SNMP, SNMPv1, SNMPv2c and SNMPv3
(USM and VACM), are all completely supported,
andso the user does not have to learn the
detailed underlying differences between
the three SNMP versions. User
can always uses a A single unified interface is used
to build SNMP agents for all speaking different SNMP
can has the flexibility to create three different types
of agent: a traditional monolithic agent, a dedicated
subagent only, and a flexible or master/ and subagent. Master/subagent architecture is
based on standard AgentX protocol. Agent eXtensibility (AgentX)
technology, is a standard protocol that
overcomes a very real needallows one to dynamically extend the managed objects in a node. This e protocol
allows you havingpermits a single SNMP
Aagent and several
Ssubagents that canto
connect and register several managed objects simultaneously without
having to interrupting
the management service. This makes way the whole management
system can be more flexible, as each subagent can be closer to its the managed information and
the SNMP extensible Aagent needs to
be started only once.
For details on about the AgentX protocol, please refer to RFC 2741.
Agent builder is built on
top of Java Management
Extensions (JMXTM) technology, a standard for instrumenting manageable resources and developing
dynamic agents. Each MIB table and group is modeled as a standard
MBean s. An MBean (Managed Bean) is a Java object that
implements a specific interface and conforms to certain design patterns. It encapsulates attributes
and operations through their public methods, and
exposes them to management applications according to follows thestandard
design patterns for exposing them to management applications.
Those sStandard MBeans specify the
public operations accessible to for SNMP clients.
A GUI-based application can
automatically generates MBeans
for the according to specified MIBs.
When the agent starts up, it registers all MBeans
with MBeanServer. Upon receiving an SNMP request from
a client, this server employs a quick search algorithm
is employed to find the corresponding
MBean and delegates part of the task to it.
Developers do not have to learn details about JMX
in detail, but , however, they must be aware that only
methods in the MBean s
interfaces are accessible from outside the agent. Although
MBean ’s implementation classes have
moreadditional public methods, some of
them are not accessible from to SNMP snmp managers.