Splitting String into Array Errors - arrays

Question

Trying to write a script that will be run in WinPE, that essentially gets the IP address of the localhost and chooses an action based on the IP range.
In Windows, the script runs flawlessly. However, in WinPE, I'm getting the following error:
script.vbs(1,1) Microsoft VBScript runtime error: Subscript out of range
Google-fu is telling me that has something to do with my array being outside of the range. Here I thought I had a decent understanding, but apparently not.
Code that works as is on Windows:
Option Explicit
Dim sIP, sHostname,sPingBat
Dim aIP
Dim iOct1, iOct2, iOct3, iOct4, iReturn
Dim oWMIService, oCmd, oAdapter
Dim cAdapters
iReturn = 999
sHostname = "."
Set oWMIService = GetObject("winmgmts:{impersonationLevel=impersonate}!\\" & sHostname & "\root\cimv2")
Set cAdapters = oWMIService.ExecQuery("Select IPAddress from Win32_NetworkAdapterConfiguration Where IPEnabled = True")
Set oCmd = CreateObject("Wscript.Shell")
For Each oAdapter in cAdapters
If Not IsNull(oAdapter.IPAddress) Then
sIP = Trim(oAdapter.IPAddress(0))
Else
iReturn = 404
WScript.Quit iReturn
End If
Next
sIP = CStr(sIP)
aIP = Split(sIP, ".")
iOct1 = CInt(aIP(0))
iOct2 = CInt(aIP(1))
iOct3 = CInt(aIP(2))
iOct4 = CInt(aIP(3))
Now, if I change the declaration of the aIP array to either of the following:
aIP()
aIP(4)
and run
aIP = Split(sIP, ".")
I get
script.vbs(26, 1) Microsoft VBScript runtime error: Type mismatch
Changing the array assignment / split line to
aIP() = Split(sIP,".")
results in
script.vbs(26, 1) Microsoft VBScript runtime error: Subscript out of range
So I'm obviously doing something wrong.
It's also entirely possible that my original error message is completely unrelated to my array range, and WinPE just doesn't like my script (in which case, if anybody has any pointers, it'd be appreciated)
At the moment, I'm mounting my wim to get the install packages to make sure the WMI and Scripting packages are installed from the ADK.

Answer 1

There is nothing wrong with the code except the assumption being made about what Win32_NetworkAdapterConfiguration returns.
From MSDN - Win32_NetworkAdapterConfiguration class
Array of all of the IP addresses associated with the current network adapter. This property can contain either IPv6 addresses or IPv4 addresses. For more information, see IPv6 and IPv4 Support in WMI.
Because sIP could contain an IPv6 address the Split() will not work as expected. IPv6 addresses don't contain . as a separator so Split() will return a Array containing the original string as the first index only. Hence attempting to read anything other then aIP(0) will cause an
Microsoft VBScript runtime error:
Subscript out of range
error.
To avoid this use InStr() to check for the existence of . in the sIP variable first, you will also need to iterate through the oAdapter.IPAddress array to check each address to get the correct one, you can't assume IPAddress(0) will always be the right one.
Try this
Dim ips, ip
For Each oAdapter in cAdapters
ips = oAdapter.IPAddress
If IsArray(ips) Then
For Each ip In ips
If InStr(1, ip, ".") > 0 Then
sIP = Trim(ip)
Exit For
End If
Next
If Len(sIP) > 0 Then Exit For
Else
iReturn = 404
WScript.Quit iReturn
End If
Next
Untested on iPad sorry

Answer 2

I guess sIP variable contains some string which can not be splitted wity delimiter "."(ex: "somestringwithNoDOT")
So in the 1st case
aIP = Split(sIP,".") ' Split("somestringwithNoDOT",".")
statement returned only 1 string, which can not be coverted to Integer. So i returned Type mismatch error in below line
iOct1 = CInt(aIP(0)) ' returns Type mismatch error
In the 2nd case
aIP() = Split(sIP,".") ' Split("somestringwithNoDOT",".")
above statement will return 1 element, but aIP is array with NO elements. So this statement rturned "Subscript out of range" error
Resolution for this issue is to check whether correct value is passing to sIP