SNMP Agent

This example shows how to use SNMP to control an embedded system.

The Simple Network Management Protocol (SNMP) is mainly used in network management systems to monitor network-attached devices for conditions that warrant administrative attention. It is the most popular network management protocol in the TCP/IP protocol suite.

The following picture shows an exemplary connection of the development board and a Computer.

SNMP agent hardware setup

Project Organization

The SNMP Agent project is available as part of the Network Reference examples.

Application Source Files

Following files implement application-specific logic in the example:

• SNMP_Agent.c contains the application main thread which initializes the Network Component.
• SNMP_Agent_MIB.c contains the mib_data_table. Change this to the application's needs.

Software Components Configuration Files

Configuration files for the software components used in the project are available in the ./RTE/ directory and can be modified to adjust the operation of related components.

Following configuration files are provided with this example:

• For the Network component, in ./RTE/Network/ folder:
  • Net_Config_SNMP_Agent.h: SNMP Agent configuration.
  • Net_Config_UDP.h: UDP Socket configuration.
  • Net_Config_ETH_0.h: Ethernet Interface configuration.
  • Net_Config.h: Network Core configuration.
  • Net_Debug.h: Network Debug configuration.
• For the CMSIS components, in the ./RTE/CMSIS/ folder:
  • RTX_Config.h and RTX_Config.c: CMSIS-RTX Configuration files for the RTOS Kernel.

When a board layer is added to the project, corresponding configuration files for the board and device components will become available in the local ./Board/ directory.

Board Layer

In order to build the project it shall be extended with a compatible board layer that provides following interfaces as connections:

• CMSIS_ETH: CMSIS-Driver for Ethernet interface
• CMSIS_VIO: CMSIS-Driver for Virtual I/O interface
• STDOUT: Standard Output redirection

Build the Project

Working with MDK-Middleware Examples explains the workflow for accessing, configuring and building an MDK-Middleware example project for your target hardware.

1. Open the Network MDK-Middleware reference example.
2. Make sure the compatible board layer is configured.
3. Select SNMP_Agent as an active project for the build process.
4. Build the project and observe that no errors are reported.

Run the Example

Hardware Setup

Board-specific hardware setup such as jumpers, Ethernet ports, power supply, etc. is documented in the board layer description (README.md) of your selected target.

1. Load the executable image to the target development board.
2. Use an Ethernet cable to connect your development board to the local area network. The PC is assumed to be already in this LAN.

Example execution

To test this example, run the Windows application SNMPTest.exe that is available as part of Keil MDK uVision and is located in <install_dir>\ARM\Utilities\SNMPTest\Release\ folder, where <install_dir> refers to the Keil MDK uVision installation directory. The program runs stand-alone without installation.

Type in the IP address of your Embedded SNMP Agent and click Connect. When connected, you can change the LCD text on the target, control the on-board LED diodes and monitor the state of on-board push-buttons.

SNMP Test Application