Mobile phone presence check/network binding question

I want to report if my android mobile phone is registered in my WLAN or not. using the network binding it was running fine until I crashed my openhab installation with some backup/resore experiments. however, now I get the thing not running correct anymore. when I do not use my phone the item changes to offline. It seems Im not using arping anymore and cant find out why.
I changed from arping to iputils-arping, same results. can run arping without sudo…

the thing:
network:pingdevice:Matthias_Handy [hostname=“”, retry=9, timeout=5000, refresh_intervall=60000, allowSystemPings=“false”]

the item:
Switch Matthias_Handy <man_3> {channel=“network:pingdevice:Matthias_Handy:online”}

properties in PaperUI shows uses_arp_pings no


any idea?
how do I set the uses_arp_pings to yes in the things configuration?

When you start do you see errors from Network binding in the logs indicating it can’t find the arping utility?

What is the contents of your network.cfg or the network binding config in PaperUI?

hi, I do not see errors regarding the arping utility in either events.log nor openhab.log

[11:23:02] openhabian@openHABianPi:~$ arping -I eth0
ARPING from eth0
Unicast reply from [3E:46:D8:A9:7D:EE] 217.289ms
Unicast reply from [3E:46:D8:A9:7D:EE] 138.376ms

I can`t find a network.cfg file, do I need to create it manually?

here`s my network binding