NETSH scripts: add network functionality to batch files

Batch files have long been a go-to solution for automating tasks in Windows, and while some may debate their relevance, they remain a powerful tool for streamlining workflows. Among the many utilities available, NETSH stands out as a versatile command-line tool that allows you to integrate advanced network functionality into your batch files. Whether you’re managing network configurations locally or remotely, NETSH can simplify complex tasks with just a few lines of code. In this guide, we’ll explore what NETSH is, how it works, and how you can leverage it to supercharge your batch files.

What is NETSH?

NETSH (Network Shell) is a command-line scripting utility that provides access to a wide range of network-related functions. It allows you to view and modify network settings, making it an invaluable tool for system administrators and power users. With NETSH, you can manage everything from DHCP settings to firewall configurations, all from the command line. What’s more, it works seamlessly across various versions of Windows, from Windows 2000 to the latest Windows 11.

Why Use NETSH in Batch Files?

Batch files are all about automation, and NETSH takes this to the next level by enabling you to handle network tasks programmatically. Instead of manually configuring network settings or running repetitive commands, you can write a batch file that uses NETSH to do the heavy lifting. This not only saves time but also ensures consistency and accuracy in your network management tasks.

How NETSH Works: Command Mode vs. Batch Mode

NETSH operates in two primary modes: Command Mode and Batch Mode. Understanding the difference between these modes is key to using NETSH effectively.

Command Mode

Command Mode is ideal for executing single, standalone commands. For example, if you want to display the configuration of a DHCP server, you can use the following command:

NETSH DHCP SHOW SERVER

Note: You must have the DHCP Server role installed on the system before you can use the command line tools.

In this example:

• NETSH initializes the shell.
• DHCP specifies the context (in this case, DHCP-related commands).
• SHOW SERVER is the actual command being executed.

Once the command runs, the NETSH shell exits, and no further commands can reference the results of the previous command.

Batch Mode

Batch Mode is more powerful and is used when you need to execute multiple commands that depend on each other. For instance, if you want to display DHCP server information and then modify a setting based on that output, you’ll need to use Batch Mode.

To use Batch Mode, you’ll need to create two files:

1. A script file containing the NETSH commands.
2. A batch file that calls the script file using the EXEC command.

For example, if your script file (dhcp_script.txt) contains:

DHCP
SHOW SERVER

Your batch file would call it like this:

NETSH EXEC dhcp_script.txt

This approach ensures that all commands are executed within the same NETSH session, allowing them to share context and results.

Working with Contexts in NETSH

NETSH organizes its functionality into contexts, which are essentially modules that provide commands for specific areas of network management. For example, the DHCP context lets you manage DHCP servers, while the RAS context handles remote access settings.

Loading Contexts

To use a context, simply enter its name. For example, to load the RAS context, you’d type:

RAS

Once inside a context, you can execute commands specific to that area. For example, within the RAS context, you can manage IP, IPX, or AppleTalk settings.

Nested Contexts

Some contexts contain sub-contexts, known as nested contexts. For example, the RAS context includes sub-contexts like IP and IPX. To switch between nested contexts, simply enter the name of the sub-context. For instance, to move from the RAS context to the IP sub-context, you’d type:

IP

Switching Between Unrelated Contexts

Switching between unrelated contexts (e.g., moving from RAS to DHCP) requires a bit more effort. NETSH provides two commands for managing context switches: PUSHD and POPD.

• PUSHD: Adds the current context to a stack and switches to a new context.
• POPD: Removes the most recent context from the stack and returns to the previous context.

For example, to switch from the RAS context to the DHCP context, you’d use:

PUSHD RAS
POPD
PUSHD DHCP

This sequence ensures that you can navigate between contexts without losing your place.

Practical Example: Automating Network Tasks with NETSH

Let’s say you want to create a batch file that:

1. Displays the current DHCP server configuration.
2. Configures a static IP address.
3. Resets the firewall settings.

Here’s how you could do it:

Step 1: Create the Script File (network_script.txt)

DHCP
SHOW SERVER
INTERFACE IP SET ADDRESS "Ethernet" STATIC 192.168.1.100 255.255.255.0
FIREWALL RESET

Step 2: Create the Batch File (run_network.bat)

NETSH EXEC network_script.txt

When you run run_network.bat, it will execute all the commands in network_script.txt in sequence, automating the entire process.

Final Thoughts

NETSH is a powerful tool that can transform the way you manage network configurations through batch files. While it may seem daunting at first, mastering its command-line interface opens up a world of possibilities for automating complex tasks. Whether you’re working with DHCP, firewalls, or remote access, NETSH provides the flexibility and control you need to get the job done efficiently. So, the next time you find yourself performing repetitive network tasks, consider reaching for NETSH — it might just become your new best friend.

TEST.TXT:

interface ipv4 set address name=”wintun” source=static addr=192.168.123.1 mask=255.255.255.0

run.bat:

@echo off
echo Executing netsh commands…
netsh exec TEST.TXT