This program re-implements the functionality of the arpcatch daemon in OpenBSD (e.g. it will listen on a network interface and reply to ARP requests with whatever MAC address it is configured to for a given IP).
The configuration file format is thus:
[global] iface=eth0 # the interface to listen on. will be put in to promiscuous # mode by Scapy [mappings] 192.0.2.1=ab:ab:ab:ab:ab:ab # define your mappings here in the ..... # form IP=MAC
It ran for more than 5 years on a small LAN (~100 machines) which had previously been served by an OpenBSD box running arpcatch. Nothing has exploded yet, but you run this code at your own risk. This package is released in to the public domain.
This package depends on Scapy.