Scapy vs Cisco Layer 2 Defenses: Crafting and Spoofing Packets
Craft spoofed ARP and IP packets with Scapy against a Cisco IOS-XE lab, then watch Dynamic ARP Inspection drop every forgery and name the attacker's real MAC.
Scapy
Crafting packets by hand when no tool does what you need. Articles tagged Scapy cover building frames field by field, replaying and fuzzing them on the wire, and using them to prove a control behaves as claimed.