How does Chromecast device communicate with the app without the WiFi password?

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  1. GeoUSA

    GeoUSA Well-Known Member

    Just curious and a little surprised no one asked. What tech is used for the app to see the Chomecast device when the new device doesn't know your WiFi password?

    There's a brief message that your home network may be unavailable for a brief period so I guess there's some layer of communication happening outside of the standard WiFi protocol.

  2. KOLIO

    KOLIO Guides Guide

    Not sure if this answers your question,but I had to log-in to my WI-FI w/the same password as I do w/any other device on my network.

    After the first log-in,the CHROMECAST behaves as any other device on my network,not needing repeated log-in attempts.

    If you're wondering if others can log-in/use your CHROMECAST w/their devices,only if they have your WI-FI password.

    Please forgive me if I'm out in left field on this........ ;)
  3. GeoUSA

    GeoUSA Well-Known Member

    I appreciate the response, but think about this -- the notebook or smartphone with the app asked for your WiFi password. The Chromecast device did not. How did the app "see" the Chromecast device, know its ID number, and communicate with it when the dongle device should not have been able to join your WiFi network fresh from the box?
  4. KOLIO

    KOLIO Guides Guide

    I think I have a grasp on what you're getting at.This article from C-NET hints at what I believe are your concerns:

    How hotel Wi-Fi killed my Chromecast travel dreams | TV and Home Theater - CNET Reviews
    RichSz likes this.
  5. lcneed

    lcneed Well-Known Member

    When you first run the Chromecast setup program on your laptop (or PC), you will notice that you were actually disconnected from your home wifi router and connected directly to the Chromecast via wifi. When the box on your laptop pops up and asked you for the WiFi password, it is actually Chromecast asking you for the ssid and password.. you are storing your ssid and password into Chromecast.

    Here are the connections:

    Laptop - WiFi Router - Internet
    Chromecast - Nothing

    -Run Chromecast Setup Program
    Laptop - Chromecast
    - Chromecast got the SSID and password from your laptop and store them

    Laptop - WiFi Router - Internet
    Chromecast - WiFi Router - Internet
    KOLIO likes this.
  6. GeoUSA

    GeoUSA Well-Known Member

    Thanks. You are basically confirming my suspicion that it is using a method to do an end-run around the security/encryption in our WiFi routers. The CNET article shared by Kolio indicates they had success with the app and Chromecast communicating but when the dongle returned to standard use of the hotel's WiFi connection the dongle was not prepared to supply room number and last name and failed at that point. I am starting to wonder what other uses or potential security weaknesses this makes possible.
  7. dautley

    dautley VIP Member VIP Member

    In response to the linked CNET article, I still have unlimited data on my phone (and yes I pay Verizons $30.00 a month tethering fee) and use my phone as a hotspot then connect my Chromecast and Nexus 7 to that network and am able to stream to anything with a open HDMI port! :)
    lcneed and KOLIO like this.
  8. mrhomiec

    mrhomiec Well-Known Member

    ohh, that's why i was unable to use my desktop through LAN to configure my Chromecast. it kept saying to enable Wi-Fi, but this makes sense.

    i ended up having to use my phone, download the Chromecast app, and use that to do the initial setup.

    afterwards, then my LAN desktop was able to send stuff over to Chromecast.
  9. legalkill

    legalkill Well-Known Member

    I think maybe you are overthinking this. Wi-Fi devices can see each other , especially when programmed to specifically regardless of the network. The password is just the credential to see the router so that the chromecast can be setup to get the internet from a router, but locally they can sense other wifi devices in range. Usually the wifi adapters are basically meant for one thing connecting to a dhcp router, so your wifi connection program is set to only locate and authenticate wifi routers that are broadcasting their function. The chromecast app uses wifi to sense the chromecast locally to access the setup.

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