ARPreplay - MAC address Spoofer

ArpRelay will forward IP packets between to machines on an Ethernet who have each been told that the MAC address of the other is some random spoofed MAC address. As far as I know, ARP relaying has until now only been publicized as method to enable sniffing in switched environments. It can obviously also be used to rewrite the packets as you forward them.

ARPrelay uses libnet and pcap and can edit the payload of the proxied packets. Since this is just proof-of-concept code, the user interface is very crude.