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wireless networking - Can two devices with the same MAC address be on the same network?


What happens if there is a device already connected to a wifi network, and subsequently another device tries to join the wifi network using the exact same MAC address as the original?



Answer



A MAC address is supposed to be unique. If someone sabotages that then two devices on the network will claim to be the same unique NIC. That simply does not work.


Just how it breaks depends on the card and possibly on the driver.



Imagine two people in the same building. Both claiming to be employee number 1.
The left employee #1 shouts 'may I have some coffee?'
Someone fetches coffee and shouts 'Coffee for employee #1 is ready'.
That person now gets two replies, one 'thanks!' and 'Hey, I did not order coffee'.


And just which of the Employee #1's answers first might depend on how busy that person is, adding some more chaos to it.


So briefly: things break.


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