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@joncutrer
Last active July 21, 2020 00:08
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This script listens for ARP request packets using scapy to learn the IP and Mac Address of LAN hosts. Learn more about this script at https://jcutrer.com/python/scapy-arp-listener
#!/usr/bin/env python3
"""scapy-arp-listener.py
Listen for arp packets using scapy to learn the IP and Mac Address of LAN hosts
Copyright (C) 2018 Jonathan Cutrer
License Dual MIT, 0BSD
"""
from __future__ import print_function
from scapy.all import *
import time
__version__ = "0.0.1"
def handle_arp_packet(packet):
# Match ARP requests
if packet[ARP].op == ARP.who_has:
print('New ARP Request')
print(packet.summary())
#print(ls(packet))
print(packet[Ether].src, "has IP", packet[ARP].psrc)
# Match ARP replies
if packet[ARP].op == ARP.is_at:
print('New ARP Reply')
print(packet.summary())
#print(ls(packet))
return
if __name__ == "__main__":
sniff(filter="arp", prn=handle_arp_packet)
@franciscopaglia
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franciscopaglia commented Jul 21, 2020

Nice! Thank you! I had to make a small tweak and define the corresponding values for the OpCode field in the ARP packet:

who_has = 1;
is_at = 2;

# ...

if packet[ARP].op == who_has
if packet[ARP].op == is_at

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