Perform your dns lookup online with our online nslookup uptool. You can use this
service for free to help troubleshoot any local area network Domain Name
Servers issues. For more information on specific nslookup command parameters
please visit Nslookup.Nexperts.Org
What is NSLOOKUP?
NSLOOKUP is a service to look up information in the DNS (Domain Name System [
RFC1034,
RFC1035,
RFC1033]). In simple terms the Domain Name System converts
the Ip addresses, like yours
38.103.63.61
, that computers use to talk to each other over a network, to names the we can
understand as humans. This name is called a Domain Host Name or just a host
name for short. Your Hostname is
Unkown hostname
So why use DNS host names?
It is a lot easy to remember and type in host name like
Google.com than to rember an IP Address like
64.233.167.99. If we had to do this navigating the world wide web would
be a confusing and time cosuming task. Host names are also used for other
purposes besides navigating the internet. A DNS Mail Exchanger record or MX
Record, allows email servers to locate and communicate with one other so we can
send email over the internet. This is just on of the many functions provided by
Domain Name Servers. A Domain Name Server or DNS Server, a computer that is
running the Domain Name System service. This allows the server to convert IP
Address to Hostnames and vice versa.
More about the NSLookup tool
The NSLookup utility is a standard tool installed in most modern operating
systems. On a windows PC you can access NSLOOKUP from the command prompt.
Click on the start menu, click run and type in "cmd" (windows 2000 and newer)
or "command" for pre-windows 2000 computers. A little black window called
command prompt should pop up. Type in NSLOOKUP followed by a domain name like
Yahoo.com. You should get results just like the ones you receive from
the nslookup tool on this web page.
So if I can use nslookup on my own computer, why do I need this web
page. Companies and corporations, including your own Internet Service
provided own their own DNS server that communicate with other Domain Name
Servers on the internet. Some times, as will all computers, these servers
experience issues. You can use this tool to trouble shoot such
problems. Also, you can see how your web hosting company has your email
set up, or even troubleshoot issues sending email over a network or the
internet.
NSLookup tips, tricks and hacks.
One drawback of using the NSLookup utility on your personal computer is that you
can't easily work with the results, (ie copy and paste specific DNS Records or
IP addresses. Here are some tips to help you manipulate the data
retrieved from the NSLookup utitily.
-
If you right click on the NSLookup command prompt window, you can choose select
all and the copy to copy the results to past into other applications.
-
You can copy a DNS Hostname or IP address and paste that information into a
command prompt window by right clicking the command window. You can't use
keyboard short cuts for copy and past information.
-
To cancel out or stop an nslookup query you can press the control and C keys at
the same time to abort the current operation.
-
An nslookup query can take several seconds, you can retrieve the information by
redirecting the out put to another application faster than the time it takes to
retrieve the results.
Working with NSLookup output Redirection: You can
redirect the results of the NSLookup utility to a text file directly from the
command line. Try it out.
-
Redirect out put to a text file:Click on your start menu, click run, and the
type in the following code. cmd /c "nslookup aol.com >>
desktop\NSLookupaol.txt"
-
This code queries the nslookup service and outputs the results directly into a
file on your desktop called nslookupaol.txt
-
Now you can freely copy and paste any portion of the nslookup results as easily
as you like.
-
To save the results to a web page try this command cmd /c "nslookup aol.com
>> desktop\NSLookupaol.htm"
NSLookup Switches
-
Here are some switches and their syntax for making special queries to the
NSlookup utility.
-
nslookup.exe -querytype=MX DNShostname
-
Returns the Mail Exchanger records
-
nslookup.exe -querytype=A DNShostname
-
Returns the hosts ip address
-
nslookup.exe -querytype=NS DNShostname
-
Returns the Name Server records
-
nslookup.exe -querytype=Cname DNShostname
-
Returns Cname or Alias records
-
nslookup.exe -querytype=SOA DNShostname
-
Returns the State Of Authority records
-
nslookup.exe - querytype=LOC DNShostname
-
Returns the Location records
-
nslookup.exe -querytype=TXT DNShostname
-
nslookup.exe -querytype=PTR DNShostname
-
Returns the Pointer Domain records
-
nslookup.exe - querytype=RP DNShostname
-
Returns the Responsible Person records
Working with Scripts and NSLookup: There are several activeX
controls and thrid party extensions on the internet today for DNS Queries to
emulate the features of the Nslookup utility. However, if your like me,
your creative, don't like to pay for things you don't have and would rahter
implement your own solution. There are a few ways to access the NSlookup
tool through built in Windows Active X controls.
-
Using Javascript. To access NSLookup with javascript we will create a
Windows Script Host Active X object called the Wscript.Shell. Here's an
example on how to use javscript in a web page to access the nslookup service
from your own computer.
<html>
<head>
<Title>Javascript and NSLookup in a web page</Title>
<script type='text/javascript'>
function dolookup() {
var domain = document.getElementById("domain")
if (domain.value=="")
{
alert('Please Enter a Domain Name');
domain.focus;
return;
}
var shell = new ActiveXObject("wscript.shell");
var cmd = 'cmd /c'
cmd += ' nslookup '
cmd += document.getElementById("domain").value;
cmd += ' >> c'
cmd += ':\\'
cmd += 'aolnslookup.txt'
var ForReading = 1, ForWriting = 2;
var fso=new ActiveXObject("scripting.filesystemobject");
if(fso.FileExists("c:\\aolnslookup.txt")){
fso.DeleteFile("c:\\aolnslookup.txt");
}
shell.run(cmd, 0, true);
alog = fso.OpenTextFile("c:\\aolnslookup.txt",ForReading);
var s;
s= alog.ReadAll();
alog.close();
alog = null;
shell = null;
fso = null;
var resultstag = document.getElementById("nsresults");
resultstag.innerHTML = '<pre>'+s+'</pre>';
}
</script>
</head>
<body>
Javascript NSLookup.
Type in the Domain you wish to query records for.
<br>
<input id="domain" type="text"> <input type="button" onclick="dolookup()"
value="NSLookup">
<br>
<br>
<div id="nsresults"></div>
</body>
</html>