Test for connectivity to MAC address

Configuration
1

I would like to set up an automation to cycle the power on a relay based on whether a network device is connected on the local LAN.

But, I would prefer to use the device’s MAC address to eliminate any possible change in IP address causing failure in the future.

Can anyone help with this?

I imagine an NMAP-type scan based on MAC address.

Thank you!

2

You can use the NMAP tracker integration combined with device tracker integration

Then set your automations based on presence

Edit:
You can also consider using ping with hostname if that’s possible, that’ll also prevent issues with changing IP addresses, and is going to be more efficient.
Or simply setting a static for the device on your router

3

Thank you so much.

If ping would be more efficient, I can do that with either hostname or static ip.

4

In case anyone is interested, this is the code I used to get this to work.

I’m sure it is primitive by the standards of the experts here, but it’s more than I could create a couple weeks ago:

alias: THR316-Attic State is off
description: ""
trigger:
  - platform: state
    entity_id:
      - binary_sensor.ping_thr316_shelly1
    from: null
    to: "off"
    for:
      hours: 0
      minutes: 10
      seconds: 0
condition:
  - alias: Unable to ping THR316
    condition: state
    entity_id: binary_sensor.ping_thr316_shelly1
    state: "off"
    for:
      hours: 0
      minutes: 2
      seconds: 0
action:
  - service: notify.notify
    data:
      message: Ping lost to 125THR316-Attic
      title: HA Notify
  - service: notify.notifier_name
    data:
      message: THR316 Attic Lost Connectivity
  - service: notify.mobile_app_iphone
    data:
      message: test notification
    enabled: true
  - service: switch.turn_off
    data: {}
    target:
      entity_id: switch.shelly_shsw_1_e8db84d6d456
  - delay:
      hours: 0
      minutes: 0
      seconds: 5
      milliseconds: 0
  - service: switch.turn_on
    data: {}
    target:
      entity_id: switch.shelly_shsw_1_e8db84d6d456
mode: single