Syste.net namespace provide the infomation about IP Address .


If you pass localhost in GetHostByName return the IP Address of local machine .

Imports System.Net
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
Dim hostname As IPHostEntry = Dns.GetHostByName(TextBox1.Text)
Dim ip As IPAddress() = hostname.AddressList
TextBox1.Text = ip(0).ToString()
End Sub
End Class