House Wifi Logged me on anyway ?

[RJSV]

   Hello !
   I'm one of those (poor suckers) blessed with infinite curiosity, about the world's technical devices, and thus questioning the house Wifi here, after storm power blackouts.

   Bringing system back up, I noticed my Android powered phone had a text message:
   "Sign on to WIFI;  RickJames"

   OK, that made sense, as the server re-booted connection to Comcast customer here at the house.   BUT,  a couple minutes later I noticed the phone notification bar had switched from cellphone (towers I guess), back to the more usual Wifi !
   I was, like, 'Auto-logged' in, without supplying my Wifi password...nice because I was contemplating the tired old 'searching', through various random spiral notebooks....for 'Almighty Password'.   "Maybe the blue one"  I was
thinking, dreading the low-tech password backup distraction.

   Wondering, tho, why that server was so casually putting me back on the local network ?

Thanks for reading.
- - Rick B.

[edpalmer42]

AFAIK, your phone wants to be online so it checks both cellular and Wi-Fi for connectivity.  It chose Wi-Fi either automatically or because you chose that as the preferred connection.

Meanwhile, computers and phones will log into Wi-Fi automatically if you checked the box that says to do that when you first set up the connection.

Ed

[ebastler]

Just to clarify, since Ed did not spell it out: Your phone has stored the password, from when you first connected manually to that WiFi network. The network wouldn't let you in "casually" without the password.

[RJSV]

   Thanks.
   I had been thinking, a theory, that the system would revert to checking that my data traffic was coming from same phone number...that sort of thing, like bank / debit cards are starting to use, including the biometric stuff.
   I keep edging up to signing up for beginner classes, here at nearby recreation dept.

[Halcyon]

Cellular data doesn't originate from your phone number, in fact, it has nothing to do with your number at all, nor do you even need a number to access data via a cellular networks (data SIMs for example). It works using regular TCP/IP like the rest of the internet.

[IanB]

Cellular data doesn't originate from your phone number, in fact, it has nothing to do with your number at all, nor do you even need a number to access data via a cellular networks (data SIMs for example). It works using regular TCP/IP like the rest of the internet.

I had never thought about that. It means you could basically use cellular data only, and then make calls using VOIP. Especially since data plans are often cheaper than voice plans.

[tom66]

I think what you were seeing is the "airport gateway" detection of your phone (also used in other public places).

Essentially, if you try to use airport Wi-Fi, the airport's router will intercept your traffic and present you with a place to log in - maybe they want to charge extra bucks for wi-fi or just get your personal info, whatever it is, but they want to show this page.  Since virtually all web traffic now is HTTPS, they do this by blocking all HTTPS traffic and forcing you over to HTTP to one specific destination.  If this sounds dodgy, well, it kinda is. 

Most likely during the power outage your router generated some kind of error page come up saying "Internet not available, call <1-800-WE-SUCK> to speak to someone clueless".  And your phone thought that was a captive gateway so it presented the message saying "log in now" (because some of those gateways do want you to log in).

Ultimately it doesn't mean anything, as soon as the connection actually is restored your phone tests that it can reach a HTTPS endpoint and assumes the connection is OK.  Your phone will permanently store the Wi-Fi credentials and you shouldn't have to re-enter those.

https://developer.android.com/about/versions/11/features/captive-portal

[RJSV]

Yeah thanks.
   Another thing that led me to think in terms of the Wifi server, is that my bank will sometimes use my in-coming phone # to 'recognize' I'm calling, and then the automatic voice might ask for the last four digits of my Social Security number.
   I think in that case the bank folks wished to (safely) accommodate some of the 'dottering' old fools, that in these times still function, albeit just barely (that'd be myself).   Old, borderline incoherent fools like myself, have become a major 'powerblock' these days, due to better longevity.
   (Thanks, I see that's not the case, with my Log-In question here.)

[m k]

Cellular data doesn't originate from your phone number, in fact, it has nothing to do with your number at all, nor do you even need a number to access data via a cellular networks (data SIMs for example). It works using regular TCP/IP like the rest of the internet.

I've once used a data SIM for regular Android "phone" stuff.
The result was that map was fine but location didn't update.

E,
maybe the device was already booted from the ecosystem.

[Halcyon]

Yeah thanks.
   Another thing that led me to think in terms of the Wifi server, is that my bank will sometimes use my in-coming phone # to 'recognize' I'm calling, and then the automatic voice might ask for the last four digits of my Social Security number.
   I think in that case the bank folks wished to (safely) accommodate some of the 'dottering' old fools, that in these times still function, albeit just barely (that'd be myself).   Old, borderline incoherent fools like myself, have become a major 'powerblock' these days, due to better longevity.
   (Thanks, I see that's not the case, with my Log-In question here.)

You can have a cellular voice service (using your mobile number) but that call is routed via Wi-Fi. It's both handset and carrier dependent, but at the end of the day, most large carriers don't care how your call reaches their network (whether it be via their towers or your own internet connection).

I'm with Telstra (Australia's largest carrier) and they call it "Wi-Fi Calling". You can read about it here:  https://www.telstra.com.au/support/mobiles-devices/telstra-wifi-calling

If your phone/carrier supports this, your home internet connection essentially acts as your own private "cell". Great for homes where cellular coverage is marginal indoors. Calls will seamlessly route from your Wi-Fi network to the carrier network (say you take a call inside your house, but then jump in the car and drive away).

[retiredfeline]

Essentially, if you try to use airport Wi-Fi, the airport's router will intercept your traffic and present you with a place to log in - maybe they want to charge extra bucks for wi-fi or just get your personal info, whatever it is, but they want to show this page.  Since virtually all web traffic now is HTTPS, they do this by blocking all HTTPS traffic and forcing you over to HTTP to one specific destination.  If this sounds dodgy, well, it kinda is.

Actually what they do is initially put you in a walled garden where connections to the outside are not allowed via NAT, with the exception of any external sites needed, e.g. for authentication. After you have satisfied their requirement (watch some ads, sign up, pay money, whatever) then normal NAT is allowed.