Obtain MAC Address from Devices using Python

Question

I'm looking for a way (with python) to obtain the layer II address from a device on my local network. Layer III addresses are known.

The goal is to build a script that will poll a databases of IP addresses on regular intervals ensuring that the mac addresses have not changed and if they have, email alerts to myself.

Answer 1

A simple solution using scapy, to scan the 192.168.0.0/24 subnet is as follows:

from scapy.all import *

ans,unans = arping("192.168.0.0/24", verbose=0)
for s,r in ans:
    print("{} {}".format(r[Ether].src,s[ARP].pdst))

Answer 2

Sounds like you want to monitor ARP spoofers? In this case, all you need is arpwatch, available in every well-supplied Linux distribution near you. Download sources here: http://ee.lbl.gov/