What is ARP, and what is ARP spoofing?

ARP (Address Resolution Protocol) is how devices on a local network find the hardware address that belongs to an IP address, for example to deliver traffic to the router. Because ARP trusts whatever answer arrives, an attacker on the same network can send false answers and pretend to be the router or another device. This is ARP spoofing, and it lets the attacker read or alter traffic passing through, a form of man-in-the-middle attack. Managed switches have protections against it. NetSenX raises ARP spoofing alerts from the Pro plan, on segments it monitors.

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