How does iPhone respond to a router that loses its internet?

Schtibbie

macrumors 6502
Original poster
Jan 13, 2007
306
3
This may be too technical a question for this forum, but here goes -- I have Time Warner Cable plus my own wifi router. Never had troubles. But recently each morning I wake up to find that, while I can reach my router via wifi (router settings), I cannot hit the internet anymore (via iPhone, macbook, or anything else). Which means my phone, which was plugged in all night, and on WIFI, and expecting to receive notifications and stuff over THAT connection, might not have been doing so for much of the night, right?

Does the iPhone (iOS) notice that, while it has a wifi connection, it does NOT have internet access anymore? Does it switch to listening for traffic on the cellular connection? Or is it not that smart and it basically goes radio deaf to everything but phone calls and non-iMessage texts?

Anyway, I have to reboot the modem and/or router each morning and then it's good again.
 

TWO2SEVEN

macrumors 68040
Jun 27, 2010
3,522
709
Plano, TX
My guess is that it switches back to LTE.

Did you have any notifications before the router problem that you aren't getting now?
 

Bobby Corwen

macrumors 68030
Jul 16, 2010
2,723
474
This may be too technical a question for this forum, but here goes -- I have Time Warner Cable plus my own wifi router. Never had troubles. But recently each morning I wake up to find that, while I can reach my router via wifi (router settings), I cannot hit the internet anymore (via iPhone, macbook, or anything else). Which means my phone, which was plugged in all night, and on WIFI, and expecting to receive notifications and stuff over THAT connection, might not have been doing so for much of the night, right?

Does the iPhone (iOS) notice that, while it has a wifi connection, it does NOT have internet access anymore? Does it switch to listening for traffic on the cellular connection? Or is it not that smart and it basically goes radio deaf to everything but phone calls and non-iMessage texts?

Anyway, I have to reboot the modem and/or router each morning and then it's good again.
Correct

It knows.
 

antiprotest

macrumors 65816
Apr 19, 2010
1,446
248
All you have to do is to leave your iPhone connected to the router, and then unplug your router from the wall. Then you can test all you want.
 

Schtibbie

macrumors 6502
Original poster
Jan 13, 2007
306
3
All you have to do is to leave your iPhone connected to the router, and then unplug your router from the wall. Then you can test all you want.
No, i'm not talking about the router going down. I'm talking about the scenario where your router is just fine, power-wise (and your phone is signed onto it and has the full-bars-of-wifi icon on it), but that router has for some reason lost internet access through the modem it's plugged into. Or the modem has lost it. Either way. If I open safari and try to web surf, it just spins and spins and NEVER seems to figure out that it really needs to switch to cellular! It would spin forever that way, I'm convinced.

THAT's why I worry that if I had a notification trying to get through the interwebs to my phone, it would never arrive. And I only worry about THAT because I'm on call sometimes (for work) and I get contacted various ways.
 

antiprotest

macrumors 65816
Apr 19, 2010
1,446
248
No, i'm not talking about the router going down. I'm talking about the scenario where your router is just fine, power-wise (and your phone is signed onto it and has the full-bars-of-wifi icon on it), but that router has for some reason lost internet access through the modem it's plugged into. Or the modem has lost it. Either way. If I open safari and try to web surf, it just spins and spins and NEVER seems to figure out that it really needs to switch to cellular! It would spin forever that way, I'm convinced.

THAT's why I worry that if I had a notification trying to get through the interwebs to my phone, it would never arrive. And I only worry about THAT because I'm on call sometimes (for work) and I get contacted various ways.
Right, I was talking about unplugging router, not from the power, but from whatever is providing Internet access. My router is connected directly to the wall. If it's connected to a modem, disconnect from the modem.

Wouldn't the router still broadcast a SSID?
 

TWO2SEVEN

macrumors 68040
Jun 27, 2010
3,522
709
Plano, TX
No, i'm not talking about the router going down. I'm talking about the scenario where your router is just fine, power-wise (and your phone is signed onto it and has the full-bars-of-wifi icon on it), but that router has for some reason lost internet access through the modem it's plugged into. Or the modem has lost it. Either way. If I open safari and try to web surf, it just spins and spins and NEVER seems to figure out that it really needs to switch to cellular! It would spin forever that way, I'm convinced.

THAT's why I worry that if I had a notification trying to get through the interwebs to my phone, it would never arrive. And I only worry about THAT because I'm on call sometimes (for work) and I get contacted various ways.

If it is that big of a worry I would just turn wifi off at night.

Do you have your emails on push? If so, do you have new email in the morning? That may tell you whether or not push is still working.
 

Schtibbie

macrumors 6502
Original poster
Jan 13, 2007
306
3
Right, I was talking about unplugging router, not from the power, but from whatever is providing Internet access. My router is connected directly to the wall. If it's connected to a modem, disconnect from the modem.

Wouldn't the router still broadcast a SSID?
Yeah, router still broadcasts SSID and the iPhone thinks it's a perfectly good thing to camp out on (though it cannot reach the internet). I'm gonna try that experiment tonight manually (yank it from the modem) or let it fail overnight and then have my wife email me or something to see if it somehow goes "around" the bad wifi connection and through cellular. I have no idea what to expect.

Given how Safari behaves, I don't think the phone is aggressive enough in getting off a non-internet-connected WIFI connection.
 

blhoward2

macrumors 6502a
Sep 19, 2012
524
12
If the router is on and you're connected, the phone will not revert back to LTE just because the Internet becomes unreachable.

The phone wouldn't even know it is offline. There is no good way to check for this. It could just be that the destination is blocked in the router, the destination is offline, etc.

Also, buy a better router.
 
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