Here is a strange one! known_devices.yaml and a linksys router

Configuration
1

I know this is likely not a HA issue but I can’t find an answer anywhere on this.

When I first set up device tracking using my linksys router it found all of my devices correctly including my chromecast audio device. I set all of the devices I didn’t want track as false. so far so good.

Now the strange part is that over the last three or four months I have these phantom devices showing up in my known_devices file with the same device id but with a different numeric suffix appended and a different MAC address.

    ## this is the first one discovered and is the real chromecast audio device##    
    ca7d0a53d3b4cd9991f8feab9d71864c:
      hide_if_away: false
      icon:
      mac: 54:60:09:F2:A3:08
      name: chromecast audio
      picture:
      track: false
      vendor: Google, Inc.
    
    ## the rest of these were discovered later ##
    
    ca7d0a53d3b4cd9991f8feab9d71864c_2:
      hide_if_away: false
      icon:
      mac: FC:2D:5E:1C:06:AB
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false
      vendor: zte corporation

    ca7d0a53d3b4cd9991f8feab9d71864c_3:
      hide_if_away: false
      icon:
      mac: 68:54:FD:57:06:AB
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false
      vendor: Amazon Technologies Inc.

    ca7d0a53d3b4cd9991f8feab9d71864c_4:
      hide_if_away: false
      icon:
      mac: 54:60:09:F2:06:AB
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false
      
    ca7d0a53d3b4cd9991f8feab9d71864c_5:
      hide_if_away: false
      icon:
      mac: 54:60:09:F2:20:D3
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false

    ca7d0a53d3b4cd9991f8feab9d71864c_6:
      hide_if_away: false
      icon:
      mac: A0:C9:A0:A3:E0:BF
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false
    .
    .
    .
    ca7d0a53d3b4cd9991f8feab9d71864c_18:
      hide_if_away: false
      icon:
      mac: 54:60:09:F2:D0:1D
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false

    ca7d0a53d3b4cd9991f8feab9d71864c_19:
      hide_if_away: false
      icon:
      mac: 54:60:09:F2:00:C0
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false

    ca7d0a53d3b4cd9991f8feab9d71864c_20:
      hide_if_away: false
      icon:
      mac: 54:60:09:F2:B8:B5
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false

    ca7d0a53d3b4cd9991f8feab9d71864c_21:
      hide_if_away: false
      icon:
      mac: 68:54:FD:57:00:A8
      name: ca7d0a53-d3b4-cd99-91f8-feab9d71864c
      picture:
      track: false

As you can see, I’m now up to 21 of these devices.

Now the stranger part is if I go and look at all of the active devices that are showing up in my router management all of those devices show up there with all of the different MAC addresses but they all have the same IP address:

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It seems that every few days or a week a new device is created with a new MAC address but it gets the same name and the same IP address.

I don’t get it.

Anyone have any idea where this is coming from?

2

So i have this router but not this problem. You need to identify the device. I doubt this is the router.

As for HA, it’s just doing it’s job. It’s creating the device each time because it see’s it as a new device mainly because of the mac address.

To me, this is a device with a malfunctioning network card. I have one device that does something similar to this once every 5 months. So i’ll randomly have a new network device that disappears, but then it reverts back to it’s correct mac address and everything is good.

The good news is that you have the IP address, so unplug/turn off crap until that IP address is gone from your network. That’s probably the best way to determine the device.

EDIT:

Just to clarify, most devices have more than 1 mac address. There is a mac address for the device, and a mac address for the network card. The network card mac address should never appear.

3

Sorry, that’s not quite right.
A MAC address is used to address a network interface on a medium (layer 2).
Every (wifi/ethernet) interface has a specific MAC address - there’s no need for a generic MAC address that’s assigned to “the device”.
If you see multiple MAC addresses on a device, it’s because it has multiple (physical or virtual) interfaces.

That being said, I’m afraid I’m not much of help.
I do own a Linksys router, but it’s running DD-WRT, so it’s not of much use here.

The strange thing is that the discovered MAC addresses have Google and Amazon vendor prefixes.
The device name looks like a strangely formatted IPv6 address to me.
I have no clue what could be causing this, though.

Sebastian

4

I rebooted my chromecast audio device and they are all gone now except the real one with original MAC address. Hopefully they won’t start coming back over time.

I understand the Google prefix but I’ve got no idea why they would show up as Amazon devices. I didn’t buy it from Amazon either.

Google tech support was basically useless. When He asked what the problem was and I told him I had 21 chromecast devices showing up on my network but physically only had one he said “that’s not a problem…” :roll_eyes: Then the person told me it was impossible because each device only has one MAC address. Obviously that’s the way it’s supposed to work.