EOe1-A User Manual - Products

Chapter 5. SNMP Operations
5.1 Simple Network Management Protocol
5.1.1 SNMP Overview
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Chapter 5 SNMP Operations
The Simple Network Management Protocol (SNMP) is one of many protocols in the Internet Protocol (IP) suite. SNMP
is the protocol recommended specifically for the exchange of management information between hosts residing on IP
networks. Network management allows you to monitor and control network devices remotely using conventional
computer network technology.
The SNMP management functions of the EOe1-A are provided by an internal SNMP agent, which utilizes in-band
communication over standard 10/100BASE-TX Ethernet. The SNMP agent is compliant with the SNMPv1 standard.
SNMP communication uses the User Datagram Protocol (UDP). UDP is a connectionless transport protocol, part of the
IP suite. The SNMP protocol is an asynchronous command/response polling protocol and operates at the OSI Layer 7
(Layer 7 is the Application Layer. Other examples of IP protocols that operate at this layer are FTP, Telnet, SMTP, etc.).
All management traffic is initiated by the SNMP-based network management station. Only the addressed managed
entity (agent) answers the polling of the management station (except for trap messages).
All functions and settings accessible via the serial terminal connection or Web of the EOe1-A are also readable and
settable via the Simple Network Management protocol.
5.1.2 SNMP Operations
The SNMP protocol includes four types of operations:
getRequest Command for retrieving specific value of an "instance" from the managed node. The managed node
responds with a getResponse message.
getNextRequest Command for retrieving sequentially specific management information from the managed node. The
managed node responds with a getResponse message.
setRequest Command for manipulating the value of an "instance" within the managed node. The managed node
responds with a getResponse message.
trap Management message carrying unsolicited information on extraordinary events (that is, events which occurred not
in response to a management operation) reported by the managed node.
5.1.3 The Management Information Base
The management information base (MIB) includes a collection of managed objects. Managed objects are defined as
parameters that can be managed, such as specific information on device configuring or on performance statistics values.
The MIB includes the definitions of relevant managed objects (MIB variables) for the specific node. Various MIB's can
be defined for various management purposes, types of equipment, etc. The management data itself is a collection of
integer, string and MIB address variables that contain all the information necessary to manage the node.
A leaf object’s definition includes the range of instances (values) and the "access" rights:
Read-only Instances of an object can be read, but cannot be set.
Read-write Instances of an object can be read or set.
Write-only Instances of an object can be set, but cannot be read.
Not accessible Instances of an object cannot be read, nor set.