I am new to networking as such, but I have been searching a lot about the problem of finding IP from MAC for the past couple of days. I have a device whose MAC address I know and I have an Android app running in my smart phone. I need to find the IP of the said device so that I can send requests to it.
On the same subnet the ways I found were to either use an external cloud server or to ping all devices in the subnet and read the ARP table. I don't want to use an external server so I went with ARP and its working fine...
However, for the case of a different subnet I am not sure how to accomplish this. Is this possible? If it is not, addition of what extra knowledge could make it possible?
Let's say I have the IP of the router that the device is connected to or the Gateway IP which the device connects to..can I use any of those to reach the device's subnet somehow? ( I really am pretty new so bear with me if I am saying something stupid)