Check for Internet Connection - Xtreme Visual Basic Talk

01-26-2003, 06:56 AM

Lachy

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Check for Internet Connection

How do I accurately check if a computer has a connection to the internet?

01-26-2003, 07:20 AM

dgdolins1

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Posts: 124

Code:

Private Declare Function InternetAttemptConnect _
    Lib "wininet" (ByVal dwReserved As Long) As Long
_______________________________________________

Private Sub Form_Load()
  If Not InternetConnectionExists Then
    MsgBox "Internet connection is not present.", vbCritical, "Error"
  End If
End Sub
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Public Function InternetConnectionExists() As Boolean
    InternetConnectionExists = (InternetAttemptConnect(ByVal 0&) = 0)
End Function

01-26-2003, 08:07 PM

Lachy

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Thanks a lot.

01-26-2003, 10:03 PM

Lachy

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Location: England

Posts: 126

Now that i've tested it, i've found a problem. I am using ADSL, which uses 2 LAN connections to operate. One of the connections is perminant, which the other one is only active when you're connected to the Internet.

If only ONE of these connections is active, the function will return TRUE. But I do not have a connection to the internet.

01-27-2003, 07:31 AM

Garmour

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Does your ADSL connection use DHCP (Dynamic addressing). If so then you could interrogate the second LAN connection to see if it has an ip address.

Dos commands like IPCONFIG /ALL do this, along with API calls like
GetNetworkParams or GetAdaptersInfo

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....but then, what would I know ?

01-27-2003, 03:14 PM

alcaholjunkie alcaholjunkie is offline

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maybe if you could get the gateway address of the adsl/cable modem then you could probly ping it to see if it is conneted.

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