How do you Identify the interface of a packet while listening to network traffic on all devices?

Question

I am writing a python program that needs to listening to traffic on all networking devices and identify packets based on their incoming interface. To listen on all interfaces I started my capture without specify a device, but I am unable to denote the interface of a particular packet. How is this done?

Answer 1

I assume that the MAC address is sufficient information for you.

The first 6 octets of a packet is the destination MAC address, which is immediately followed by the 6 octets of source MAC address.

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