ActiveSocket Toolkit Add network capabilities to any Windows or .NET application

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Sending SNMP Traps using Visual Basic .NET

ActiveSocket provides an easy-to-use development interface (SDK) to a variety of IP protocols. By using ActiveSocket, you can very easily create or enhance applications with network features.

ActiveSocket features the following: DNS, FTP, HTTP, HTTPs, ICMP Ping, IP-to-Country, MSN, NTP, RSH, SCP, SFTP, SNMP v1/v2c (Get, GetNext, Set), SNMP Traps, SNMP MIB, SSH, TCP, Telnet, TFTP, UDP, Telnet, Wake-On-LAN and more.

ActiveSocket is compliant with SNMP versions v1 and v2c. Several SNMP data types are supported, including:

  • ASN_INTEGER; Numeric values;
  • ASN_INTEGER32; Numeric values;
  • ASN_BITS; Bit values, for instance: one bit per port to see if a port is connected;
  • ASN_OCTETSTRING; Byte string;
  • ASN_NULL; Null value;
  • ASN_OBJECTIDENTIFIER; Object identifier (OID);
  • ASN_SEQUENCE; Text string;
  • ASN_IPADDRESS; IP address;
  • ASN_COUNTER32; 32 bit counter;
  • ASN_GAUGE32; 32 bit gauge;
  • ASN_TIMETICKS; Timestamps or uptime;
  • ASN_OPAQUE; Byte string;
  • ASN_COUNTER64; 64 bit counter;
  • ASN_UNSIGNED32; unsigned 32 bit numeric value.

ActiveSocket supports the following SNMP trap features:

  • SNMP v1 and SNMP v2c support;
  • Support for alphanumeric OID's (object identifier) and numeric OID's;
  • Multithreading architecture: send and/or receive SNMP traps simultaneously from one process using multiple threads;
  • Support for ports other than the default 161 and 162 ports;
  • Support for enterprise specific traps;
  • Support for SNMP v1 generic traps such as coldstart, warmstart, linkup, linkdown, authfailure and neighbourloss;
  • Send multiple data objects (variable bindings) using a single SNMP trap message.

ActiveSocket can be well integrated into Visual Basic .NET environments. This document describes how ActiveSocket can be integrated into Visual Basic .NET projects.

Prerequisites

IMPORTANT: Make sure that the SNMP Service is installed and running on the machine where ActiveSocket is installed. For more details, please read FAQ items Q1200010 and Q1200015.

Step 1: Download and install the ActiveSocket Toolkit

Download the the ActiveSocket Toolkit from the ActiveXperts Download Site and start the installation. The installation guides you through the installation process.

Step 2: Create a new Visual Basic .NET Project

Launch Microsoft Visual Studio (for instance 'Microsoft Visual Studio 2005') from the Start menu. Choose 'New' from the 'File' menu and click on 'Project'. In the 'New Project' dialog, select a Visual Studio template (for instance: 'Console Application'). Select a name for the application (for instance: 'DemoApp') and a name for the solution (for instance: 'DemoSolution'). Also, select the directory where you want to store the project (for instance: 'C:\MyProjects):

Visual Basic dotNET

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Step 3: Refer to the ActiveSocket Library

Now that a new project has been created, you must add a reference to the ActiveSocket Toolkit in the project to be able to use the the ActiveSocket object. To do so, choose 'Add Reference...' from the 'Project' menu. In the 'Add Reference' dialog that pops up, select the 'COM' tab and select the 'ActiveSocket 3.1 Type Library' as shown in the following picture:

Visual Basic.NET

(Click on the picture to enlarge)

Click 'OK' to close the 'Add Reference' dialog.

Step 4: Declare and create the object

To send SNMP traps using Delphi, you need to declare and create the following ActiveSocket objects:

  • SnmpTrapManager; The SNMP manager which allows you to send and/or receive SNMP traps in the form of SnmpTrap objects;
  • SnmpTrap; The actual SNMP trap, this object holds some SNMP trap properties like: destination host, port and community, specific and generic trap and a timestamp;
  • SnmpObject; This object is used to hold the data to be send with the SNMP trap. These data objects are also called variable bindings.

On top of your code, type the following line to use the ActiveSocket namespace:

Imports ASOCKETLib

In your Main function, declare and create the following objects:

	Public m_objSnmpTrapManager As SnmpTrapManager
	Public m_objSnmpTrap As SnmpTrap
	Public m_objSnmpObject As SnmpObject

	m_objSnmpTrapManager = New SnmpTrapManager()
	m_objSnmpTrap = New SnmpTrap()
	m_objSnmpObject = new SnmpObject()

Step 5: Sending a trap

When the required SNMP objects are created, you can implement the code to send a SNMP trap:

Private Sub ButtonSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CommandSend.Click
    ' Declare local variables
    Dim objSnmpTrap As SnmpTrap
    Dim objSnmpObject As SnmpObject

    ' Create local objects
    objSnmpTrap   = New SnmpTrap()
    objSnmpObject = New SnmpObject()

    ' Set the data to be send with the trap (variable binding)
    objSnmpObject.OID = TextOID.Text
    objSnmpObject.Type = GetTypeAsLong()
    objSnmpObject.Value = TextValue.Text

    ' Set the trap properties (destination, community) and add the data
    objSnmpTrap.Host      = TextAgent.Text
    objSnmpTrap.Port      = CInt(TextPort.Text)
    objSnmpTrap.Community = TextCommunity.Text
    
    objSnmpTrap.AddObject (objSnmpObject)

    ' Set the protocol version used by the manager
    objSnmpTrapManager.ProtocolVersion = ComboVersion.SelectedIndex + 1

    ' Send the trap
    objSnmpTrapManager.Send ( objSnmpTrap )
End Sub

You can download the complete sample on our ftp site ftp.activexperts-labs.com/samples/network-component. There are many other working ActiveSocket scripts on our site and shipped with the product.