DNS NsLookup using an HTML Form
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.
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.
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.
When using HTML, there are two ways to install the Network Component on a client PC:
- Automatically using HTML code;
- Using the Network Component InstallShield installation.
Automatic installation using HTML code
You can install the Network Component automatically using the following HTML code on top of the HTML page:
<head>
<object codebase="https://www.activexperts.com/files/network-component/3.1/AxNetwork32.cab"
classid="CLSID:B52B14BA-244B-4006-86E0-2923CB69D881" ></object>
</head>
The Network Component will be installated automatically. The user will be asked to confirm the installation, because the DLL is coming from an untrusted site (www.activexperts.com).
There are two ways to avoid prompting:
- Add the ActiveX/COM location to the user's trusted sites. You can manage trusted manually (by using the Internet Explorer), through a logon script (by appyling the registry change from the logon script) or by using Active Directory Group Policies;
- OR use a trusted location for the DLL. For instance your Intranet site, because most probably this site has already been added to the list of trusted sites for all users.
Manual installation using the Network Component installation procedure
On each client PC, download the Network Component from the ActiveXperts Download Site and start the installation. The installation guides you through the installation process.
Step 2: Create the Network Component object in HTML
You must use Javascript to declare and create the object:
var objDnsServer; objDnsServer = new ActiveXObject ( "AxNetwork.DnsServer" );
Appendix: Full source code
<html>
<head>
<title>ActiveXperts Network Component Sample - DNS</title>
<object codebase="https://www.activexperts.com/files/network-component/cab/4.4/axnetwork32.cab" classid="CLSID:B52B14BA-244B-4006-86E0-2923CB69D881" style="visibility: hidden;"></object>
<style>
.clbody {
font-family:Verdana, Arial, Helvetica, sans-serif;
font-size:9pt;
font-weight:normal;
}
.clfooter {
font-family:Verdana;
font-size:7pt;
font-weight:normal;
}
h1, .h1 {
width:100%;
font-family:Verdana, Arial, Helvetica, sans-serif;
font-size:18px;
font-weight:bold;
}
hr, .hr {
color:#b0b0b0;
}
</style>
<script language="JavaScript" type="text/javascript">
<!--
var objConstants = new ActiveXObject("AxNetwork.NwConstants");
var objDnsServer = new ActiveXObject("AxNetwork.DnsServer");
function getInfo()
{
document.getElementById("fldAxNetworkInfo").innerHTML = "Build: " + objDnsServer.Build + "; Module: " + objDnsServer.Module
}
function getDnsRecord()
{
var objForm = document.forms["AXForm"];
var numLastError = 0;
var strLastError = "";
var strResponse = "";
objDnsServer.Server = objForm.CTL_DNSSERVER.value;
//objDnsServer.LogFile = "c:\dns.log"; // Optional: set LogFile property for troubleshooting purposes
objDnsServer.Lookup( objForm.CTL_HOST.value, objConstants.nwDNS_TYPE_ANY );
numLastError = objDnsServer.LastError;
if( numLastError == 0 ){
objDnsRecord = objDnsServer.GetFirstRecord();
while ( objDnsServer.LastError == 0 ){
strResponse = strResponse + GetDnsRecordInfo( objDnsRecord );
objDnsRecord = objDnsServer.GetNextRecord();
}
}
strLastError = objDnsServer.GetErrorDescription( numLastError );
objForm.CTL_RESULT.value = numLastError + " : " + strLastError;
objForm.CTL_RESPONSE.value = strResponse;
}
//-->
</script>
</head>
<body onload="getInfo()">
<h1>ActiveXperts Network Component Sample - DNS</h1>
<hr size="1">
<form name="AXForm">
<table class ="clbody">
<tr>
<td valign="top">Component:</td>
<td valign="top"><span id="fldAxNetworkInfo"></span></td>
</tr>
<tr>
<td valign="top">DNS Server:</td>
<td valign="top"><input style="width: 500px" type="text" name="CTL_DNSSERVER" value="ns1.interstroom.nl"></td>
</tr>
<tr>
<td valign="top">Host:</td>
<td valign="top"><input style="width: 500px" type="text" name="CTL_HOST" value="activexperts.com"></td>
</tr>
<tr>
<td valign="top"> </td>
<td valign="top"><input size="25" type="button" onclick="getDnsRecord()" value="Lookup" name="CTL_SUBMIT" style="height: 23px; width: 500px"></td>
</tr>
<tr>
<td valign="top"> </td>
<td valign="top"> </td>
</tr>
<tr>
<td valign="top">Result code:</td>
<td valign="top"><input type="text" name="CTL_RESULT" disabled="true" style="border: 0px; width: 500px;"></td>
</tr>
<tr>
<td valign="top">Query results:</td>
<td valign="top"><textarea style="width: 500px" name="CTL_RESPONSE" rows="10" cols="60"></textarea></td>
</tr>
</table>
<br>
<br>
</form>
<hr size="1">
<div>
This sample is based on ActiveXperts Network Component, an <a target="_blank" href="https://www.activexperts.com">ActiveXperts Software</a> product.<br>
<a href="../Index.htm">Click here</a> to return to the HTML sample menu page.<br>
</div>
</body>
</html>
<script language="JavaScript" type="text/javascript">
<!--
function GetDnsRecordInfo( objDnsRecord )
{
var numType = objDnsRecord.Type;
var strInfo = "";
switch( numType )
{
case objConstants.nwDNS_TYPE_A:
strInfo = strInfo + "Type : A\n";
strInfo = strInfo + "Name : " + objDnsRecord.Name + "\n";
strInfo = strInfo + "IPv4 Address : " + objDnsRecord.Address + "\n";
case objConstants.nwDNS_TYPE_AAAA:
strInfo = strInfo + "Type : AAAA\n";
strInfo = strInfo + "Name : " + objDnsRecord.Name + "\n";
strInfo = strInfo + "IPv6 Address : " + objDnsRecord.Address + "\n";
case objConstants.nwDNS_TYPE_CNAME:
strInfo = strInfo + "Type : CNAME\n";
strInfo = strInfo + "Name : " + objDnsRecord.Name + "\n";
strInfo = strInfo + "Alias : " + objDnsRecord.Address + "\n";
case objConstants.nwDNS_TYPE_MX:
strInfo = strInfo + "Type : MX\n";
strInfo = strInfo + "Name : " + objDnsRecord.Name + "\n";
strInfo = strInfo + "Preference : " + objDnsRecord.Preference + "\n";
strInfo = strInfo + "Mail Exchange : " + objDnsRecord.MailExchange + "\n";
case objConstants.nwDNS_TYPE_NS:
strInfo = strInfo + "Type : NS\n";
strInfo = strInfo + "Name : " + objDnsRecord.Name + "\n";
strInfo = strInfo + "Name Server : " + objDnsRecord.NameServer + "\n";
case objConstants.nwDNS_TYPE_PTR:
strInfo = strInfo + "Type : PTR\n";
strInfo = strInfo + "Name : " + objDnsRecord.Name + "\n";
strInfo = strInfo + "Host : " + objDnsRecord.Address + "\n";
case objConstants.nwDNS_TYPE_SOA:
strInfo = strInfo + "Type : SOA\n";
strInfo = strInfo + "Name : " + objDnsRecord.Name + "\n";
strInfo = strInfo + "Name Server : " + objDnsRecord.NameServer + "\n";
strInfo = strInfo + "MailBox : " + objDnsRecord.MailBox + "\n";
strInfo = strInfo + "Serial : " + objDnsRecord.SerialNumber + "\n";
strInfo = strInfo + "Refresh : " + objDnsRecord.RefreshInterval + "\n";
strInfo = strInfo + "Retry Interval : " + objDnsRecord.RetryInterval + "\n";
strInfo = strInfo + "Expiration Limit : " + objDnsRecord.ExpirationLimit + "\n";
strInfo = strInfo + "Minimum TTL : " + objDnsRecord.MinimumTTL + "\n";
}
strInfo = strInfo + "TTL : " + objDnsRecord.TTL + "\n\n";
return strInfo;
}
//-->
</script>
You can download the complete samples here. There are many other working Network Component scripts on our site and shipped with the product.