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Question

Is there any way to send a popup message from a Linux systen to a "random" laptop/tablet/mobile linked to my Wireless network ? For example, if I let my WLAN open and I see a not recognized computer connected to it, is there anyway to send to that device a message ?

On the other hand, if I am connected to someone else open network and they may or may not be aware that their network is open, can I send them a message warning that I am accessing their network?

Is this question acceptable for this site?

PS: I have no practical application for this is just curiosity.

Answer 1

Yes, I would consider that as a valid question. You have a computer problem need to inform other users on the network looking for a solution on how to do that.

And well, I felt like answering:

You can only do this if the computer provides a service to do this, which is often enabled by default.

You could hook up into their network traffic, but that would be considered illegal; just accessing their network is actually already illegal as well. Unless you live somewhere where it is not, YMMV...

But perhaps there are interesting approaches to this that might work.