LAN-Tech Network Management

I was recently asked how to change the DNS server IP’s in the NIC configurations of numerous servers, which of course have static IP’s.  Sounds simple right?  Maybe not.

• You can use Group Policy to do so but apparently it will not work with all O/S’s and it will only work if DNS is working. 
• You can deploy a script but that requires logon or reboot to apply. 
• You use psexec and a text file list of servers with something similar to: “psexec @textfilename netsh interface ip set dns name = “Local Area Connection” source = static addr = 1.1.1.1”  however it requires the NIC name be accurate and it is not always named “Local Area Connection”

One proposed great solution is to use a VBS script by Alexxxandre K8L0 on TechNet.  This uses a text file list of server names or IP’s and updates each in the list.  The article can be found in the following link, but since occasionally the links change or articles ‘disappear’ I have posted the content here, but I take no credit for its design: http://gallery.technet.microsoft.com/scriptcenter/Change-fixed-DNS-IP-of-422415c1

Syntax: cscript SetDNSv2.vbs inputfile outputfile dns_ips
Input file: Put IP or Hostname of server line by line on a text file.
Output file: Is a log of return status “Inputed,Host,Adapter,Return Status”
dns_ips: Ips of DNS Servers separated by commas.
Example: cscript SetDNSv2.vbs inputfile.txt outputfile.txt 10.1.0.10,10.1.0.11,10.1.0.10

‘Set DNS By k8l0
‘By k8l0
If WScript.Arguments.Count = 3 Then
    strInputFile = WScript.Arguments.Item(0)
    strOutputFile = WScript.Arguments.Item(1)
    strNewDNS = WScript.Arguments.Item(2)
Else
    wscript.echo “Sintaxe: cscript SetDNSv2.vbs inputfile.txt outputfile.txt 10.1.98.64,10.1.98.36,10.1.18.24”
    wscript.quit
end if    
 
On error resume next
 
Const ForReading = 1
Const ForAppending = 8
 
Set objFSO = CreateObject(“Scripting.FileSystemObject”) 
Set objTextFileIn = objFSO.OpenTextFile(strInputFile, ForReading)
Set objTextFileOut = objFSO.OpenTextFile(strOutputFile, ForAppending, True)
 
wscript.echo “Host        Adapter        Return Status”
wscript.echo “—-        ——-        ————-”
objTextFileOut.WriteLine(“Inputed,Host,Adapter,Return Status”)
 
Do Until objTextFileIn.AtEndOfStream 
    strComputer = Trim(objTextFileIn.Readline)
    
    Set objWMIService = GetObject(“winmgmts:” & “{impersonationLevel=impersonate}!\\” & strComputer & “\root\cimv2”)
    Set colNicConfigs = objWMIService.ExecQuery(“SELECT * FROM Win32_NetworkAdapterConfiguration WHERE IPEnabled = True”)
    
    For Each objNicConfig In colNicConfigs
        If Not IsNull(objNicConfig.DNSServerSearchOrder) Then
            strReturn = “”
            arrNewDNSServerSearchOrder = Split(strNewDNS,”,”)
            intSetDNSServers = objNicConfig.SetDNSServerSearchOrder(arrNewDNSServerSearchOrder)
            If intSetDNSServers = 0 Then
                strReturn = “””” & “Replaced DNS server search order list to ” & strNewDNS & “.” & “”””
            Else
                strReturn = “Unable to replace DNS server search order list.”
            End If
        Else
            strReturn = “DNS server search order is null. Nothing changed!”
        End If
        
        strDNSHostName = objNicConfig.DNSHostName
        strIndex = objNicConfig.Index
        strDescription = objNicConfig.Description
        strAdapter = “Network Adapter ” & strIndex & ” – ” & strDescription
        wscript.echo strDNSHostName & VBTab & strAdapter & VBTab & strReturn
        objTextFileOut.WriteLine(strComputer & “,” & strDNSHostName & “,” & strAdapter & “,” & strReturn)
        Next
Loop 
 
objTextFileIn.close
objTextFileOut.close
 
wscript.echo “Finished!!!”