If you own a Netgear router which includes the Genie network mapper, then this router will send out promiscuous requests to every IP address on your network, port 80, "/currentsetting.htm". If it gets back a response, then it updates its discovery map and then... stops pestering the host.
If the host doesn't respond, then it will be asked again and again to process/ignore these annoying requests until the end of time.
It's annoying, but one strategy might be to create a one-line response to the route "/currentsetting.htm" with contents such as:
As a benefit, anyone with a Netgear-based router would have more information about the IP and MAC address of their Raspberry Pi.
Querying an actual Netgear router:
curl http://10.20.30.1/currentsetting.htm Firmware=V2.02.18 RegionTag=C3000_NA Region=us Model=C3000 InternetConnectionStatus=Up ParentalControlSupported=1 SOAPVersion=2.0 ReadyShareSupportedLevel=1 LoginMethod=1.0