Windows Script to Change Network Settings

Automating Network Configuration with VB Script

Recently, a recurring challenge presented itself. Many professional settings necessitate adjustments to network configurations when transitioning between different networks.

Consider individuals who utilize laptops both at the office and at home. A static IP address might be configured for home use, while the workplace typically employs DHCP. This demands frequent manual alterations to network settings.

The Problem of Frequent Network Switching

This scenario is particularly prevalent among engineers and IT professionals who routinely connect to isolated networks within a building. Accessing these networks often requires switching to a static IP configuration.

Subsequently, reconnecting to the corporate network necessitates reverting to DHCP. This constant toggling can be time-consuming and frustrating.

A Solution: VB Script Automation

Having encountered this issue repeatedly, and growing weary of navigating network card settings manually, a decision was made to develop a VB script to streamline the process.

As those familiar with previous programming articles know, VB scripts are a favored tool. They have been previously utilized to create a simulated "possessed" computer and to automate data backups using Microsoft SyncToy.

Script Flexibility and User Input

Automating this task with a VB script is not only feasible but can also be designed to accept user-defined static IP addresses, enhancing its adaptability.

This article will detail the implementation of this solution, broken down into three distinct sections.

• The first section will cover the foundational elements of the script.
• The second will focus on incorporating user input for the static IP.
• Finally, the third section will demonstrate the complete, functional script.

Creating a Network Setting Change Script

To develop a utility for switching network configurations, three primary objectives must be met through scripting. Initially, the script should facilitate the creation of static IP settings. Subsequently, a script to activate DHCP is required. Lastly, the script needs to prompt the user for their desired action and execute it accordingly.

VB Script for Configuring Static IP Settings

It’s important to remember that these scripts must be saved as a text file with a .wsf extension to function correctly on a Windows operating system. The following script modifies network settings to utilize a static IP address, complete with a specified subnet mask and default gateway – all three values are directly embedded within the script itself.

For all code examples presented in this article, ensure the inclusion of "<job><script language="VBScript">" at the beginning and "</script></job>" at the end; otherwise, the code will not execute.

Here is the script designed to implement the static IP change:

Option Explicit
 
On Error Resume Next
 
Dim objWMIService
 
Dim objNetAdapter
 
Dim strComputer
 
Dim arrIPAddress
 
Dim arrSubnetMask
 
Dim arrGateway
 
Dim colNetAdapters
 
Dim errEnableStatic
 
Dim errGateways
 
strComputer = "."
 
arrIPAddress = Array("192.168.1.106")
 
arrSubnetMask = Array("255.255.255.0")
 
arrGateway = Array("192.168.1.1")
 
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
 
Set colNetAdapters = objWMIService.ExecQuery("Select * from Win32_NetworkAdapterConfiguration where IPEnabled=TRUE")
 
For Each objNetAdapter in colNetAdapters
 
 errEnableStatic = objNetAdapter.EnableStatic(arrIPAddress, arrSubnetMask)
 
 If Not errEnableStatic = 0 Then
 
 WScript.Echo "Failure assigning IP/Subnet."
 
 End If
 
 errGateways = objNetAdapter.SetGateways(arrGateway)
 
 If Not errGateways = 0 Then
 
 WScript.Echo "Failure assigning Gateway."
 
 End If
 
Next
 
WScript.Quit

This script leverages the Windows WMI service to modify network settings. The script utilizes three predefined array variables containing the IP address, subnet mask, and gateway information. It then identifies the active, enabled network adapter and employs the "EnableStatic" and "SetGateways" methods to implement the necessary changes. Upon execution on a network configured for DHCP, the script successfully altered adapter settings, resulting in a loss of internet connectivity.