Suspicious MAC discovered

Configuration
1

I’m filtering all and allow only selected MACs on my Asus router.

When I include new device on my router whitelist Home Assistant alerts me with a circular icon on the Main UI and the new device represented, all ok.

But, I have a device that is not in router whitelist and I can’t find in all my devices MACs, it’s a Cisco System mac 00:AA:6E:C0:84:19, What is this?

19

2

Delete it from known_devices.yaml and see if it comes back

3

Yes, I deleted from known_devices.yaml, reboot HA and it appears again.

00_aa_6e_c0_84_19:
  hide_if_away: false
  icon:
  mac: 00:AA:6E:C0:84:19
  name: 00 aa 6e c0 84 19
  picture:
  track: true

Only appears on HA, in my router there is nothing, only whitelisted connections (WiFi & cable are whitelisted MACs and static IP by DHCP).

4

Is your router just reporting scanned devices, not necessarily connected devices to HA?

I am not familiar with the ASUS WRT component.

5

Yes, but this MAC is only detected by HA, I don’t saw any other site, there is no signals in the router, not appears with arl -a, no appears with ping to broadcast IP…
I don’t have any Cisco device.

6

There are many devices that use CISCO hardware. It doesn’t have to be a Cisco branded device.

7

Linksys comes to mind. if somebody has a Linksys wireless card, for instance.
At one time Cisco owned Linksys.

8

I have all MACs of my house tracked, whitelisted and assigned IP by DHCP, only this MACs can access to LAN. Ghost MAC doesn’t appears in any site except HA and I can’t track.

9

What is the layer 2 mac address of your ISP? They could very well be using Cisco gear.

10

How is this a home assistant question?

11

What flavor of Home Assistant did you install?

12

Try the arp command

arp

Will give a big list of your hardware and the ip number.

13

They only see this in Home Assistant

14

I don’t know… But my ISP is outside my LAN…

15

Raspberry flavour.

16

Yes, I do it (after ping to broadcast ip) but only show my devices.

17

They are still layer 2 connected to your router so their mac address would be in the router table.

18

At last I found it, only in my router console ann typing ‘arp -a’ command show the IP associated to MAC.

xxxipxxx.myisp.com (_IP_) at 00:aa:6e:c0:84:19 [ether]  on eth0
xxxipxxx.myisp.com (_IP_) at 00:aa:6e:c0:84:19 [ether]  on eth0

Thanks to all and sorry if my topic goes outside Home Assistant questions… Only HASS shows this MAC.