Watchdog script to monitor device availability on local network?

[XIII]

I want to be notified when one particular device in my local network goes offline. I was first thinking of writing a script on a Raspberry Pi, but then I thought it might be possible on the router (RT-AC86U, running Asuswrt-Merlin 384.13) itself?

My general idea is to ping the device a couple of times (every x minutes) and if all those attempts fail send a push notification via Pushover to my mobile devices.

Does somebody already have a similar script that (s)he wants to share?

Or any tips on how to start from scratch?

 

[octopus]

I want to be notified when one particular device in my local network goes offline. I was first thinking of writing a script on a Raspberry Pi, but then I thought it might be possible on the router (RT-AC86U, running Asuswrt-Merlin 384.13) itself?

My general idea is to ping the device a couple of times (every x minutes) and if all those attempts fail send a push notification via Pushover to my mobile devices.

Does somebody already have a similar script that (s)he wants to share?

Or any tips on how to start from scratch?

Do a forum search that give you a start.

 

[Bamsefar]

I have, back home, a script that reads all wifi mac adresses, will that do?

 

[XIII]

Do a forum search that give you a start.

Did that before I posted, but I was not lucky with the search terms I used...

I have, back home, a script that reads all wifi mac adresses, will that do?

Even if it's not exactly my use case I would love to see an example that will get me started. Please share it?

 

[octopus]

Did that before I posted, but I was not lucky with the search terms I used...

What about to use "pushover" as search word, working for me.

 

[XIII]

What about to use "pushover" as search word, working for me.

I tried "watchdog", "monitor", "script", etc., but not "pushover" (because I know how to use that).

Using that term does indeed give a good start. Thank you!

 

[XIII]

I'm trying this for now; feedback is welcome!

#!/bin/sh

check_reachable() {
    ping -c1 -q -w10 "$1" >/dev/null 2>&1
}

notify() {
    curl -s \
    --form-string "token=<APP>" \
    --form-string "user=<USER>" \
    --form-string "title=AC86U" \
    --form-string "message=$1 unreachable!" \
    --form-string "sound=siren" \
    --form-string "priority=1" \
    https://api.pushover.net/1/messages.json
}

for HOST in device1 device2 device3 device4
do
    if ! check_reachable ${HOST}
    then
        notify ${HOST}
    fi
done

where device1, device2, device3, and device4 are (local) hostnames for some devices in my network.

With this line added to services-start:

cru a Reachable "55 * * * * sh /jffs/scripts/check_reachable.sh"

And this line to services-stop:

cru d Reachable

 

[octopus]

Run script with "set -x" and trace it.

 

[XIII]

Run script with "set -x" and trace it.

It’s working as far as I know.

Since I’m no script guru I am wondering if this can be improved, and how.

EDIT: Did a real-life test by disconnecting a device just before 19:55 and did get a push notification on my Apple Watch at 19:55

 

[Natey2]

I want to be notified when one particular device in my local network goes offline.

My ASUS RT-AC88U supports IFTTT.
I've used it to detect and alert me when a Roku connects to my WiFi.
It might be able to detect and alert on device disconnects too.

Sent using Tapatalk

 

[Mick Kenne]

I'm trying this for now; feedback is welcome!

#!/bin/sh

check_reachable() {
    ping -c1 -q -w10 "$1" >/dev/null 2>&1
}

notify() {
    curl -s \
    --form-string "token=<APP>" \
    --form-string "user=<USER>" \
    --form-string "title=AC86U" \
    --form-string "message=$1 unreachable!" \
    --form-string "sound=siren" \
    --form-string "priority=1" \
    https://api.pushover.net/1/messages.json
}

for HOST in device1 device2 device3 device4
do
    if ! check_reachable ${HOST}
    then
        notify ${HOST}
    fi
done

where device1, device2, device3, and device4 are (local) hostnames for some devices in my network.

With this line added to services-start:

cru a Reachable "55 * * * * sh /jffs/scripts/check_reachable.sh"

And this line to services-stop:

cru d Reachable

I am not too familiar with scripts, I have the wan notification and firmware update ones running properly and can execute them from a command line to test but when I try to do the same with this one I get

-sh: ./check_reachable.sh: not found

 

[ColinTaylor]

-sh: ./check_reachable.sh: not found

You have created the file with a Windows editor. Correct the format with the following command:

dos2unix check_reachable.sh

 

[Mick Kenne]

I used notepad++, so in the command line to execute I just type the command you posted? I tried that and got nothing Thanks for your help

 

[Mick Kenne]

nevermind I am an idiot, I got it, I was typing check-reachable not check_reachable thank you

 

[Mick Kenne]

so I am still having some trouble, when I have this line and trigger from a command line nothing happens:

cru a Reachable "55 * * * * sh /jffs/scripts/check_reachable.sh"

if I simply change it to
/jffs/scripts/check_reachable.sh

I get the pushover notification from the command line but I never actually get notified when the device I am trying to monitor goes offline, do I need to change something in the ping line?

 

[ColinTaylor]

I don't know what you mean by "when I have this line and trigger from a command line nothing happens". All that command does is schedule the script to run once an hour at 5 minutes to the hour. So you have to wait until that time.