Detecting lack of internet connections.

[bigdavidt]

We have an Access application with a subroutine that posts information to the GeckoBoard cloud service several times a day. Sometimes the connection fails, so I have added code to the subroutine that will make a second and a third attempt so as to minimize the number of fails. Lately I found out that two of the network computers that use the application have had their internet connections disabled on purpose. What can I do to help our application detect this and not try to run the subroutine?

The subroutine is like this:

Public Sub PushToGecko(gURL, payload)
On Error GoTo Err_SomeName

Dim NumOfTries As Long

'Dim objSvrHTTP
Set objSvrHTTP = CreateObject("MSXML2.ServerXMLHTTP")

Dim strT As String

Err_TryAgain:

objSvrHTTP.Open "POST", gURL, False
'MsgBox (payload)
objSvrHTTP.Send (payload)

'MsgBox (CStr(objSvrHTTP.status))

If objSvrHTTP.Status <> 200 Then
Call SendEmail("cbrown@prestwick-group.com", "None", "Dashboard Fail", "None", "One dashboard push has failed. Please fix me." & gURL)
'Call reportFailure("Dashboard fail", "Push to Gecko <> 200")
End If

Set objSvrHTTP = Nothing

Exit Sub

Err_SomeName:

If NumOfTries < 3 And (Err.Number = -2147220975 Or Err.Number = -2147483638 Or Err.Number = -2147012894 _
Or Err.Number = -2147220973 Or Err.Number = -2147012866) Then
NumOfTries = NumOfTries + 1

GoTo Err_TryAgain
End If

'Any unexpected error.
Call LogError(Err.Number, Err.description, "ReorderTrelloCards, cardID " & cardID)
Resume Next

End Sub

 

[strongm]

Try looking for error 80072EE7 (-2147012889) being returned - this means DNS failed and is a reasonable indicator that an internet connection is down (MS themselves pretty much do this to show network status in the Windows status bar - they do an DNS lookup of

http://www.msftncsi.com.

If that succeeds they then try and GET a file from the looked-up address to be really sure, but just a failed DNS should be good enough in most circumstances)