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Crumbtrail » Network Component » How to Use Network Component » SNMP MIB » Visual Basic .NET

Visual Basic .NET SNMP MIB Browser Sample Source Code

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

Network Component 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.

Network Component can be well integrated into any development platform that supports ActiveX objects.

SNMP MIB Browsing can be well integrated into ASP .NET environments. This document describes how Network Component's SNMP MIB Browser can be integrated into ASP .NET projects.

A management information base (MIB) is a database used to manage the devices in a communications network. The database is hierarchical (tree-structured) and entries are addressed through object identifiers (OID's). A MIB should contain information on these commands and on the target objects (controllable entities or potential sources of status information) with a view to tuning the network transport to the current needs. Each type of object in a MIB database has a name, a syntax, and an encoding. The name is represented uniquely as an OID. An OID is an administratively assigned name. The administrative policies used for assigning names are discussed later in this memo.

Use Network Component's 'SnmpMibBrowser' object to load a MIB database into memory and iterate over all objects and view all properties.

Step 1: Download and install the Network Component

Download Network Component 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 2008') 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):

(Click on the picture to enlarge)

Step 3: Refer to the Network Component Library and create the objects

Now that a new project has been created, you must add a reference to the Network Component in the project to be able to use the the Network Component 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 'Network Component 4.4 Type Library' as shown in the following picture:

(Click on the picture to enlarge)

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

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

Imports AxNetwork

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

Public m_objSnmpMib As SnmpMibBrowser
m_objSnmpMib = New SnmpMibBrowser()

Appendix: Full source code

Imports System.IO
Imports AxNetwork

Module SnmpMib

    Sub Main()
        Dim objConstants As AxNetwork.NwConstants = New AxNetwork.NwConstants
        Dim objSnmpMIB As AxNetwork.SnmpMibBrowser = New AxNetwork.SnmpMibBrowser
        Dim strMibFile As String = ""

        ' A license key is required to unlock this component after the trial period has expired.
        ' Call 'Activate' with a valid license key as its first parameter. Second parameter determines whether to save the license key permanently 
        ' to the registry (True, so you need to call Activate only once), or not to store the key permanently (False, so you need to call Activate
        ' every time the component is created). For details, see manual, chapter "Product Activation".
        ' objSnmpMIB.Activate("XXXXX-XXXXX-XXXXX", False)

        ' Display component information
        Console.WriteLine("ActiveXperts Network Component {0}{1}Build: {2}{3}Module: {4}{5}License Status: {6}{7}License Key: {8}{9}", objSnmpMIB.Version, Environment.NewLine, objSnmpMIB.Build, Environment.NewLine, objSnmpMIB.Module, Environment.NewLine, objSnmpMIB.LicenseStatus, Environment.NewLine, objSnmpMIB.LicenseKey, Environment.NewLine)

        ' Set Logfile (optional, for debugging purposes)
        objSnmpMIB.LogFile = Path.GetTempPath() + "SnmpMibBrowser.log"
        Console.WriteLine("Log file used: {0}{1}", objSnmpMIB.LogFile, Environment.NewLine)

        strMibFile = ReadInput("Enter MIB file (leave blank for a Windows System MIB file)", "c:\windows\system32\mib_ii.mib")

        Console.WriteLine("MIB File: " & strMibFile)
        Console.WriteLine("LoadMibFile, result: " & objSnmpMIB.LastError.ToString() & " (" & objSnmpMIB.GetErrorDescription(objSnmpMIB.LastError) & ")")
        If (objSnmpMIB.LastError = 0) Then

            ShowMIBTree(objSnmpMIB, objConstants)
        End If

        System.Threading.Thread.Sleep(5000) ' Sleep for 5 seconds 
    End Sub

    Private Sub ShowMIBTree(ByVal objSnmpMIB As SnmpMibBrowser, ByVal objConstants As NwConstants)

        Dim objSnmp As SnmpObject
        Dim strDescription, strAccess, strStatus As String
        Dim nDescription As Int32

        ' Start with "iso"
        objSnmp = objSnmpMIB.Get("")

        While (objSnmpMIB.LastError = 0)

            strDescription = objSnmp.Description.ToString().ReplaceEx(vbCrLf, " [nl] ").ReplaceEx(vbLf, " [nl] ")
            nDescription = strDescription.Length
            If (nDescription > 40) Then

                strDescription = strDescription.Substring(0, 40)
                strDescription = strDescription & "..."
            End If
            If (objSnmp.Access = objConstants.nwMIB_ACCESS_NOACCESS) Then
                strAccess = "NOACCESS"
            ElseIf (objSnmp.Access = objConstants.nwMIB_ACCESS_NOTIFY) Then
                strAccess = "NOTIFY"
            ElseIf (objSnmp.Access = objConstants.nwMIB_ACCESS_READONLY) Then
                strAccess = "READONLY"
            ElseIf (objSnmp.Access = objConstants.nwMIB_ACCESS_WRITEONLY) Then
                strAccess = "WRITEONLY"
            ElseIf (objSnmp.Access = objConstants.nwMIB_ACCESS_READWRITE) Then
                strAccess = "READWRITE"
            ElseIf (objSnmp.Access = objConstants.nwMIB_ACCESS_READCREATE) Then
                strAccess = "READCREATE"
                strAccess = "n/a"
            End If

            If (objSnmp.Status = objConstants.nwMIB_STATUS_CURRENT) Then
                strStatus = "CURRENT"
            ElseIf (objSnmp.Status = objConstants.nwMIB_STATUS_DEPRECATED) Then
                strStatus = "DEPRECATED"
            ElseIf (objSnmp.Status = objConstants.nwMIB_STATUS_OBSOLETE) Then
                strStatus = "OBSOLETE"
            ElseIf (objSnmp.Status = objConstants.nwMIB_STATUS_MANDATORY) Then
                strStatus = "MANDATORY"
                strStatus = "n/a"
            End If

            Console.WriteLine("OID: " & objSnmp.OID.ToString())
            Console.WriteLine("  Name: " & objSnmp.OIDName.ToString())
            Console.WriteLine("  Description: " & strDescription)
            Console.WriteLine("  Syntax: " & objSnmp.Syntax.ToString())
            Console.WriteLine("  Access: " & strAccess)
            Console.WriteLine("  Status: " & strStatus)

            objSnmp = objSnmpMIB.GetNext()

        End While
    End Sub

    Private Function ReadInput(ByVal strTitle As String, ByVal strDefault As String) As String
        Dim strInput As String = ""
        Console.Write("  > ")
        strInput = Console.ReadLine()
        If (strInput = "") Then
            strInput = strDefault
        End If
        ReadInput = strInput
    End Function

End Module

You can download the complete sample on our FTP site There are many other working Network Component scripts on our site and shipped with the product.

NOTE: Demo Projects are created with Microsoft Visual Studio 2008

The Network Component project ships with a set of Microsoft Visual Studio .NET samples, including samples for Microsoft Visual C# .NET. The projects are created with Microsoft Visual Studio 2008.

Users with a later version of Microsoft Visual Studio can open such a project. The Visual Studio Conversion Wizard will guide you through the process of converting the project to the version used.