Disable internet connection on Windows

11.11.2018

One time I was testing a JavaScript application which had an offline mode. That application was running in browser and was communicating with a remote server.

I wanted to test it in offline mode. By that I mean loading an application and imitating network disconnection. In the Google Chrome you can do it easily from the Developer console. However, in Mozilla Firefox and Internet Explorer it is much harder; at least I didn't find any functionality for this. Moreover, as I use it in Selenium tests I wanted a solution which is browser independent and can be fully automated.

I decide to disable internet connection on the operating system level (Windows) as it definitely would work for everything. The most straightforward way is to just disable network interface. But, I find out that it requires administrator privileges which aren't granted when you run it from other program without privileges. And, of course, it's not a good idea to run your tests as an administrator.

Solution

In Windows you can create system task which in turn runs script to disable network. As this script is run by system task it has all required privileges.

SET interface="Ethernet"

netsh interface show interface name=%interface% | findstr ^
    /R /C:"Administrative state:" | findstr /C:"Enabled"

if %errorlevel%==1 (
    echo Disabled
    netsh interface set interface name=%interface% admin=Enabled
) else (
    echo Enabled
    netsh interface set interface name=%interface% admin=Disabled
)

Put it somewhere near your tests and set it up as follows:

Change interface to name of your Ethernet interface (in script)
Open "Task Scheduler"
Click "Create Task"
Set name of the task to "toggle_connection"
Check checkbox "Run with highest privileges"
Go to "Triggers" tab and create trigger "At task creation/modification"
Go to "Actions" tab and create action "Start a program" with link to script

That's all! Now you can toggle your internet connection from Command prompt by this command:

    schtasks /Run /TN toggle_connection

Now, you can run this as system command from your program (in my case it is Python script) to toggle network connection.

Download scripts

References

Selenium