Is it possible to disable the network in iOS Simulator?

Question

I am trying to debug some inconsistent behaviour I am seeing in an application that gets its primary data from the Internet. I don't see the issues in the simulator, just on the device, so I'd like to reproduce the network and connectivity environment in the simulator.

Is there a way of disabling the network in the simulator?

(I am connecting to the Mac remotely to code, and there isn't any other choice right now, so disabling the OS network isn't an option).

Solution 1

I'm afraid not—the simulator shares whatever network connection the OS is using. I filed a Radar bug report about simulating network conditions a while back; you might consider doing the same.

Solution 2

Use a simple Faraday cage to block or limit the external RF signal level.

You can make your own with aluminum foil. The openings should be smaller than the wavelength of your data service if that's what you want to block.

• 800 MHz has a 37 cm (14") wavelength
• 1900 MHz has a 16 cm (6") wavelength.

This works better with an actual device than with the simulator since the Mac is hard to work on when inside the Faraday cage ;-)

Solution 3

Yes. In Xcode, you can go to menu Open Developer Tools → More Developer Tools and download "Additional Tools for Xcode", which will have the Network Link Conditioner.

Using this tool, you can simulate different network scenarios (such as 100% loss, 3G, high-latency DNS, and more) and you can create your own custom ones as well.

Solution 4

The only way to disable the network on the iOS simulator I know is using tools like Little Snitch or Hands Off. With them you can deny/block any outgoing and ingoing network connections.

You can set it up so that it only blocks connections from the simulator app. It works like a firewall.

Solution 5

Just turn off your Wi-Fi in Mac OS X. This works a treat!

View more solutions

Comments

[Blitz]

but that won't make the simulator behave like you're offline. It will just make your servers be unavailable, which is quite a different thing.

[rgPaiva]

actually, LordT, that may be sufficient for the specific circumstances I have...!

[rgPaiva]

marking as correct, as it answers the specific question I asked, but am also acknowledging the helpful answer from phix23.

[rgPaiva]

phix23 - do you have a preference between those two suggested tools?

[Felix]

No I haven't. I've only tried Hands off, because it has more features.

[hotpaw2]

+1 : I've used Little Snitch for exactly this purpose, testing to make sure a Simulated app works if the network connection is broken.

[samvermette]

Not sure if it's in response to this radar bug, but the Developer Tools now include a Network Link Conditioner tool.

[modocache]

Network Link Conditioner allows you to specify a percentage of packets to be dropped, but as far as I've seen there's unfortunately no way to disable all connectivity.

[liquid]

if you are on the developersite it's in the package HARDWARE IO TOOLS FOR XCODE.

[Johno]

Doesn't help the OP who specifically stated that this wasn't an option, but this is a perfect simple solution for me.

[Kevin Laity]

Just a quick suggestion, if you create a walk-in Faraday cage with a desk inside, the Mac will be much easier to work with.

[vignesh kumar]

your answer is interesting even though he asked for simulator

[Jerry]

developer.apple.com/library/ios/#documentation/DeveloperTool‌​s/…

[Gabriele Petronella]

Currently Network Link Conditioner allows to set a 100% packet loss, and it seems to work.

[Michael Robinson]

Somehow I prefer the idea of encasing my device in foil.

[Ayberk]

@race_carr Since the simulator shares the same connection, it actually works on the simulator, i.e., you can simulate those network scenarios for your app.

[fatuhoku]

Has anyone managed to get notifications of network changes to work in the simulator with Network Link Conditioner?

[fatuhoku]

It's inconvenient to not be able to see StackOverflow when debugging your app's connection problems!

[Siken]

Since the question was about the simulator, I think I'll just make one of these in Photoshop and set it as my desktop background. That will probably work, right?

[Mark Henderson]

As of today (Feb 2015) this is packaged into "Hardware IO Tools for Xcode"

[ToolmakerSteve]

Read the last line of the question: "(I am connecting to the Mac remotely to code, no other choice right now, so disabling the OS network isn't an option)." Besides, your suggestion was already given two years ago, by benpalmer.

[Will]

This 'trick' has been used for real by professionals :) Back when I worked on the first gen smart phones we used to use stout biscuit tins. Not all brands worked, but those that did were perfect.

[Kyrylo Polezhaiev]

Faraday cage can be used with WiFi router (:

[Gobe]

It is a good tool, but unfortunately I found out that the SCNetworkReachabilityFlags contains the .Reachable flag when using the "100% Loss" profile of the tool; as opposed to a real disconnected state.

[gaussblurinc]

should be accepted as correct answer! ( I'd rather use plumbum box for iKryptonite )

[Adil Hussain]

Since the Simulator shares the host machine's network connection, you can turn off internet on your host machine to simulate "network disabled". Not ideal but it works.

[Ismail Iqbal]

agreed with @Gobe unable to simulate a disconnected network with the tool

[ElegyD]

Since Xcode 8, the Network Link Conditioner is in the "Additional Tools for Xcode" package.

[Jannie Theunissen]

Thanks for logging the bug report and encouraging others to actually do something about the problem.

[Jannie Theunissen]

This also throttles the host's connection, so it is no better than pulling the plug on your developer machine -- no collaboration or internet reference. So, not a practical solution.

[Jannie Theunissen]

Also, 100% loss throttles the host's connection so, not a practical solution. If you are prepared to develop without the internet then simply pulling the plug on your developer machine is better than this solution.

[JCarlosR]

It is affecting all the mac. I want to quit the internet connection only for the simulator, because I am using the mac remotely ...

[JCarlosR]

I have a global class with a static function checking for the internet connection. Return false is a great idea. No installs, and I can continue working remotely! Thank you.

[sudo]

Wait, Network Link Conditioner applies to the entire host machine, not just the simulator. How is this useful? I can just unplug my ethernet if I want that.

[ecth]

Right now I'm on XCode 8.3.3 and they only have tools for 8.2 and 9 beta (1, 3, 4 and 6). I'll try the tools for 8.2 but still this is confusing. Why isn't this stuff simply update itself? At least whithin one major version like 8.x.

[Bill Chan]

It may not work on iOS11GM. I can not find the Wifi setting in the simulator.

[brandenbyers]

Using Siri isn't the only option with Xcode 9 now that it is possible to activate multiple apps. Activating the iOS Settings app to turn of wifi now works too.

[jbyrd]

@samvermette - as sudo said, the Network Link Conditioner tool applies to the entire host machine, not just the simulator, right?

[Chris Prince]

Any way to turn off the network while doing unit tests? stackoverflow.com/questions/46404535/… has an idea about how to do it for UI tests, but I'm testing my code not the UI.

[Chicowitz]

Now just put it in the oven to finish the job

[user924]

this is a virtual phone (simulator), not a real device... your captain

[Brian Sachetta]

I don't think I've ever laughed so hard at a S/O answer. This was great. And in a hilarious way, it actually works.

[Pablo]

Not what I'm looking for, but that was funny!

[CSawy]

Where is this isInternetAvailable defined?!

[Matrosov Oleksandr]

Reachability manager still show that I am connecting to network in case of 100% loose

[Darshit Shah]

@CSawy Its flag which send current status of internet connection in reachability class.

[Onur Şahindur]

Almost 8 year past, still the most elegant solution.

[Vilmir]

As said before, this tool does not allow to control the connection of the simulator only, it controls the connection of the entire macos.

[grego]

It's a problem when you're also hardwired then you have to disable both. Wifi is often enabled even when wired for things like AirPlay to work.

[Dean Puckett]

This might be a silly thought but, can you not just put the sim in Flight mode?

[Mohammad Reza Koohkan]

nice, great hack!

[Mariano J. Ponce]

That doesn't solve the issue of testing offline apps. It affects the OS internet as well

[Dinith Rukshan Kumara]

Only legends do this. Best & most funniest answer I ever found in stackoverflow.

[testing]

@DeanPuckett: I can't find such option in the simulator ... The control center is empty, in settings there is nothing ...

[testing]

Tried this without luck :( Especially I want to block WiFi and cell signal!

[Darkwonder]

Put an "i" in front of it, paint it white, and take my money ;D

[Darkwonder]

I couldn't download any aluminum foil from the link...