From the doc: 'Smit is a simple ARP hijacking tool for switched/unswitched networks. I based the tool on sources from arpmitm and arprelay and included nice features like automatic ARP MAC query and some improved MAC cache consistence algorithm. Now you can save the whole relayed traffic to a file (buffered, for heavy traffic and direct write mode included) and analyse it with some hex editor. The format of the capture file is still very simple, it is a raw dump of the captured ethernet frames (may change in the future or new formats will be added).'