The TCP/IP Guide  9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)       9  TCP/IP Network Configuration and Management Protocols (BOOTP, DHCP, SNMP and RMON)            9  TCP/IP Network Management Framework and Protocols (SNMP and RMON)                 9  TCP/IP Internet Standard Management Framework Overview, Architecture, Components and Concepts

Overview and History of the TCP/IP Internet Standard Management Framework and Simple Network Management Protocol (SNMP) 1 2 3 TCP/IP Internet Standard Management Framework Architecture and Protocol Components

SNMP Entities

Each device that participates in network management using SNMP runs a piece of software, generically called an SNMP entity. The SNMP entity is responsible for implementing all of the various functions of the SNMP protocol. Each entity consists of two primary software components. Which components comprise the SNMP entity on a device depends of course on whether the device is a managed node or a network management station.

An SNMP managed node can be pretty much any network device that can communicate using TCP/IP, as long as it is programmed with the proper SNMP entity software. SNMP is designed to allow regular hosts to be managed, as well as intelligent network interconnection devices such as routers, bridges, hubs and switches. Other “unconventional” devices can likewise be managed, as long as they connect to a TCP/IP internetwork: printers, scanners, consumer electronic devices, even specialty medical devices and more.

The SNMP entity on a managed node consists of the following software elements and constructs:

• SNMP Agent: A software program that implements the SNMP protocol and allows a managed node to provide information to an NMS and accept instructions from it.
  
  
• SNMP Management Information Base (MIB): Defines the types of information stored about the node that can be collected and used to control the managed node. Information exchanged using SNMP takes the form of objects from the MIB.

On a larger network, a network management station may be a separate, high-powered TCP/IP computer dedicated to network management. However, it is really software that makes a device into an NMS, so the NMS may not be a separate hardware device. It may act as an NMS and also perform other functions on the network.

The SNMP entity on a network management station consists of:

• SNMP Manager: A software program that implements the SNMP protocol, allowing the NMS to collect information from managed nodes and to send instructions to them.
  
  
• SNMP Applications: One or more software applications that allow a human network administrator to use SNMP to manage a network.

Overview and History of the TCP/IP Internet Standard Management Framework and Simple Network Management Protocol (SNMP) 1 2 3 TCP/IP Internet Standard Management Framework Architecture and Protocol Components