How to findIP address assigned by my ISP?

I am using a single winsock control for my application which has to run on a maching which has multiple network cards. The same machine is connected to internet and gets assigned IP address from the ISP each time it connects. The internet connection is a DSL connection through USB port.

The application needs to monitor the IP address given to the machine by ISP. How to single out this address??
Should I need to assign winsock to every network adapter??

This is from API-Guide 3.7:

VB Code:

'This project requires the following components:
' - a form (Form1) with a textbox (Text1, Multiline=True)
'   and a command button (Command1)
' - a module (Module1)
 
'in Form1:
Private Sub Command1_Click()
    Module1.Start
End Sub
 
'In Module1:
 
'******************************************************************
'Created By Verburgh Peter.
' 07-23-2001
' [email][email protected][/email]
'-------------------------------------
'With this small application , you can detect the IP's installed on your computer,
'including subnet mask , BroadcastAddr..
'
'I've wrote this because i've a programm that uses the winsock control, but,
'if you have multiple ip's  installed on your pc , you could get by using the Listen
' method the wrong ip ...
'Because Winsock.Localip => detects the default ip installed on your PC ,
' and in most of the cases it could be the LAN (nic) not the WAN (nic)
'So then you have to use the Bind function ,to bind to your right ip..
'but how do you know & find that ip ?
'you can find it now by this appl.. it check's in the api.. IP Table..
'******************************************************************
 
 
Const MAX_IP = 5   'To make a buffer... i dont think you have more than 5 ip on your pc..
 
Type IPINFO
     dwAddr As Long   ' IP address
    dwIndex As Long '  interface index
    dwMask As Long ' subnet mask
    dwBCastAddr As Long ' broadcast address
    dwReasmSize  As Long ' assembly size
    unused1 As Integer ' not currently used
    unused2 As Integer '; not currently used
End Type
 
Type MIB_IPADDRTABLE
    dEntrys As Long   'number of entries in the table
    mIPInfo(MAX_IP) As IPINFO  'array of IP address entries
End Type
 
Type IP_Array
    mBuffer As MIB_IPADDRTABLE
    BufferLen As Long
End Type
 
Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)
Public Declare Function GetIpAddrTable Lib "IPHlpApi" (pIPAdrTable As Byte, pdwSize As Long, ByVal Sort As Long) As Long
Sub main()
Form1.Show
End Sub
 
'converts a Long  to a string
Public Function ConvertAddressToString(longAddr As Long) As String
    Dim myByte(3) As Byte
    Dim Cnt As Long
    CopyMemory myByte(0), longAddr, 4
    For Cnt = 0 To 3
        ConvertAddressToString = ConvertAddressToString + CStr(myByte(Cnt)) + "."
    Next Cnt
    ConvertAddressToString = Left$(ConvertAddressToString, Len(ConvertAddressToString) - 1)
End Function
 
Public Sub Start()
Dim Ret As Long, Tel As Long
Dim bBytes() As Byte
Dim Listing As MIB_IPADDRTABLE
 
Form1.Text1 = ""
 
On Error GoTo END1
    GetIpAddrTable ByVal 0&, Ret, True
 
    If Ret <= 0 Then Exit Sub
    ReDim bBytes(0 To Ret - 1) As Byte
    'retrieve the data
    GetIpAddrTable bBytes(0), Ret, False
      
    'Get the first 4 bytes to get the entry's.. ip installed
    CopyMemory Listing.dEntrys, bBytes(0), 4
    'MsgBox "IP's found : " & Listing.dEntrys    => Founded ip installed on your PC..
    Form1.Text1 = Listing.dEntrys & "   IP addresses found on your PC !!" & vbCrLf
    Form1.Text1 = Form1.Text1 & "----------------------------------------" & vbCrLf
    For Tel = 0 To Listing.dEntrys - 1
        'Copy whole structure to Listing..
       ' MsgBox bBytes(tel) & "."
        CopyMemory Listing.mIPInfo(Tel), bBytes(4 + (Tel * Len(Listing.mIPInfo(0)))), Len(Listing.mIPInfo(Tel))
         Form1.Text1 = Form1.Text1 & "IP address                   : " & ConvertAddressToString(Listing.mIPInfo(Tel).dwAddr) & vbCrLf
         Form1.Text1 = Form1.Text1 & "IP Subnetmask            : " & ConvertAddressToString(Listing.mIPInfo(Tel).dwMask) & vbCrLf
         Form1.Text1 = Form1.Text1 & "BroadCast IP address  : " & ConvertAddressToString(Listing.mIPInfo(Tel).dwBCastAddr) & vbCrLf
         Form1.Text1 = Form1.Text1 & "**************************************" & vbCrLf
    Next
 
'MsgBox ConvertAddressToString(Listing.mIPInfo(1).dwAddr)
Exit Sub
END1:
MsgBox "ERROR"
End Sub

;)
-Lou