DNS NsLookup using ASP.NET (Visual Basic)

The Domain Name System (DNS) is the method by which Internet addresses in mnemonic form - such as www.activexperts.com - are converted into the equivalent numeric IP address such as 212.97.55.136. To the user and application process this translation is a service provided either by the local host or from a remote host via the Internet. The DNS server (or resolver) may communicate with other Internet DNS servers if it cannot translate the address itself.
DNS names are constructed hierarchically. The highest level of the hierarchy is the last component or label of the DNS address. Labels can be up to 63 characters long and are not case sensitive. A maximum length of 255 characters is allowed. Labels must start with a letter and can only consist of letters, digits and hyphens.

Nslookup is a popular program for UNIX, LINUX and Windows to query Internet domain name servers. It allows the user to query name servers for information about various hosts and domains or to print a list of hosts in a domain.

ActiveSocket provides an easy-to-use development/scripting interface to use the same operations as NsLookup, through the DnsServer class. By using ActiveSocket, you can very easily create or enhance Windows applications/scripts with DNS lookup features.

ActiveSocket features the following: ICMP, HTTP and HTTPs (supporting for proxy servers, secure web sites), FTP, DNS, Telnet, NTP time protocol, RSH remote shell script interface, SNMP (Simple Network Management Protcol), SNMP Traps, Sockets, WOL (Wake-On-LAN), and more.

Step 1: Download and install ActiveSocket

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

Step 2: Create a new ASP .NET VB Project

Launch Microsoft Visual Studio (for instance 'Microsoft Visual Studio 2005') from the Start menu. Choose 'New' from the 'File' menu and click on 'Web Site'. In the 'Web Site' dialog, select ASP .NET Web Site. 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):

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Step 3: Refer to the ActiveSocket Library and create the objects

Now that a new project has been created, you must add a reference to the ActiveSocket library in the project to be able to use 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 2.4 Type Library' as shown in the following picture:

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

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 object:

   Public objFtpServer As FtpServer
   
   objFtpServer    = New FtpServer()

The ActiveSocket tool is a Network Communications ActiveX software component (SDK). This control supports SNMP, SMTP, POP3, Telnet, TCP, NTP, RSH, HTTP, HTTPs, FTP, DNS, ICMP and more, and can be used by any Windows development platform, including Visual Basic .NET, Visual CSharp .NET, ASP .NET (VB,CS), ASP, Visual Basic, Visual Studio/Visual C++, Delphi, PHP, ColdFusion, HTML, VBScript and any other ActiveX/COM compliant platform. The ActiveSocket Toolkit is an ActiveXperts Software B.V. Product.