I have implemented the Reachability class successfully. However, in my app I'd like to notify the user when a connection to our server only can't be made (but the regular internet is working).
Reachability is reporting that the iPhone successfully can reach a hostname, when I thought it might return an error b/c I was not on an authenticated network:
The hostname I use is 'foreverfreebank.com'. Again, Reachability's hostname check reports success.
However,
--to access this site via the web, one needs to use https in the browser, i.e. 'https://foreverfreebank.com'
Does Reachability account for this case? Or does the protocol part ('https') not count for anything?
I am confused b/c if you type in in the Firefox browser 'http://foreverfreebank.com', (leaving out the 's'), you get an error. That is, http:// should NOT be reachable.
Similarly, I have another site that requires VPN access to get to the site: http://checksforever.com. When I try the hostname: 'checksforever.com', Reachability reports success even though I am not on VPN.
Is this expected behavior? Thanks
You need to check reachability on a specific port (443 in this case). This is something that is not supported by Reachability API. Refer to this question, or this.
Relevant part from documentation:
A remote host is considered reachable when a data packet, sent by an
application into the network stack, can leave the local device.
Reachability does not guarantee that the data packet will actually be
received by the host.
So, basically Reachability doesn't test if the remote host accepts incoming connections. For this purpose, I suspect you'll need to open an URL connection and wait for time out/other errors.
Related
I am sure there is little % of iOS developers who haven't used Reachability, directly or via some framework like Alamofire.
What I am interested what it actually does? The best guess I can make is that given host it opens sockets and then listens for said host. But what network protocol does it use, is it simple UDP (it is not http as far as I can observe), where it periodically sends packages to said host and awaits answer?
Reachability sends no packets at all. It doesn't even tell you that a host is actually reachable. It just tells you that if you made a network request, then the system has an active network interface that it would try to use. That's all. There's no promise those packets would arrive (let alone that you'd get a response), just that iOS would try to send them.
Reachability really only has a couple of uses (and most of the time shouldn't be used). It is useful if "no network is available" would cause you to modify your user interface, or to tell you that it might be a good time to re-try a previously failed connection. (Since iOS 12, you should really use NWPathMonitor for this. I don't know any good uses for Reachability since iOS 12.)
The only way that you can know that a request will actually succeed is to try to send it and see if you get a response. That's why it is not recommended that you test Reachability before sending requests. Just send the request and deal with the errors if they come, since it is always possible to have an error, even if Reachability said you could connect.
So I'm working on an IoT app, where I need to configure the hardware by connecting to its WiFi. If I use AFNetworking or URLSession to make the call, they fail with this error message.
"The Internet connection appears to be offline."
I need a way to make the API call to the local Wifi of the hardware by overriding the Reachability check. I'm sure there must be a way to do so, but I can't seem to come across something like that.
Reachability tells you if a certain host is reachable via Wifi. reachability.connection == .wifi test should be enough for that.
However, to know the reachability via that utility, you must know your host's IP within the wifi network, not internet.
What are all IP addresses that your host exposes? They will each belong to a network - internet, wifi, LAN and such.
What you probably need is the correct network utility to tell you that, for example, arp.
When I checked the apple Reachability class, it does return true even though the connected network doesn't have an active internet connection. So I'm having few doubts here -
Why is Reachability class made to throw YES if the packet can leave the local device even though it doesn't ensure it is delivered at the endpoint? Are there any special reasons to limit the ability?
Reachability has reachabilityWithHostName method still, YES will be thrown by class even if we add familiar hostname in the same network. If it doesn't ensure endpoint packet delivery why they provided this method?
Is there any other way to check whether there is an active internet connection in the connected network other than Reachability? Do we need to add our custom APIs or logic to tackle this thing?
I did connect an android phone to the same network, it instantaneously notified me the connection has no internet connection.
I used GCDAsyncUdpSocket to send udp message to discover ssdp service, in iOS reported "No route to host" this error,but there is no problem in the simulator above can be found in service, is that how it happened? I searched a lot of information, but no discovery could help me.
I've run into the same thing. Of course without your source code we can't help you other than to provide vague guesses. I hope you've fixed it by now and if you recall what the problem actually was, please let us know.
Things to check :
Firewall settings on the host. I was trying to receive messages on my mac book and found that Firewall settings can block the port you chose. Firewall is under system preferences on the 3rd tab.
Use apples Reachability class to make sure you've got an active WIFI/Cell connection to the internet. (here : https://developer.apple.com/library/ios/samplecode/Reachability/Listings/Reachability_Reachability_h.html#//apple_ref/doc/uid/DTS40007324-Reachability_Reachability_h-DontLinkElementID_7 )
You can also use other functions in the Reachability class to let you know if the host is reachable before even bothering to open up a socket.
If the host is your mac and the simulator is on the mac, there isn't much of actual network traffic and then when you run on your phone you are actually using real networking. Be aware of, depending on your networking situation, you may need the external IP address of your host (vs the internal network WIFI address e.g. 192.168.1.4 )
Some people have reported a bug where UDP stops working and you get no route to host messages but for some reason turning on and off airplane mode fixes it. Maybe check out their solution (using keep alive messages ever 30 seconds or so to prevent power management from turning off the cell connection). Here is an example : intermittent "No Route to Host" on iOS, flight mode off then on fixes
In case you are developing an App Clip for iOS app, be aware that:
a) Background Session is not supported
b) Multipath is not supported. Setting `multipathServiceType = .handover` on `URLSessionConfiguration` will cause all requests failure due to `No route to host`
I am working on a web application for iOS that is going to be accesed from a local webserver in a network that has NO internet connectivity at all.
My problem is that everytime an iOS device is locked, it disconnects from the WiFi network, so when the device is unlocked again, it has to reconnect. Part of that reconnection process is determining if there is Internet connection (which there isn't). Until the process is not finished iOS does not allow any DNS resolution (so if I write http://10.0.0.1 it will go there, but not if I request http://something.local.com).
Since we control that network, we want to know how to does iOS verifies Internet connectivity so that we can fake the responses it expects.
I don't know if it's possible to resolve DNS without an internet connection on iOS, but if that's the case, that would be a way better solution since you don't need to mess with your router settings. Use my solution only if it really isn't possible with only code.
I'll suggest you to follow this guide: http://blog.jerodsanto.net/2009/06/sniff-your-iphones-network-traffic to check which actions your iPhone executes to detect an internet connection.
Using this information you could forward the is-there-internet-requests on your router to a local server which fakes the there-is-internet-responses.
This assumes Apple really uses an external server to detect this, which I'm not sure about. But it wouldn't hurt to give it a try!
Have you looked at the Reachability Class? You don't have to use the reachabilityForInternetConnection method, which checks if a default route is available. You can use the reachabilityWithAddress: method and check if your server is reachable.