The .Net DNS class can be used to get a host name or an IP of a given host name. To use DNS class in your project, you need to include System.Net.

Include System.Net Reference.

And say I want to get IP address if http://www.huachaojune.com/. The given code will do that for you.

Imports System
Imports System.Net
Namespace DNSName
' <summary>
' Summary description for Class1.
' </summary>
Class Class1
'Entry point which delegates to C-style main Private Function
Public Overloads Shared Sub Main()
Main(System.Environment.GetCommandLineArgs())
End Sub
Overloads Shared Sub Main(args() As String)
Dim ipEntry As IPHostEntry = Dns.GetHostByName(http://www.huachaojune.com/)
Dim IpAddr As IPAddress() = ipEntry.AddressList
Dim i As Integer
For i = 0 To IpAddr.Length - 1
Console.WriteLine("IP Address {0}: {1} ", i, IpAddr(i).ToString())
Next i
End Sub 'Main
End Class 'Class1
End Namespace 'DNSName