This graph shows the number of local hosts (or addresses) into three groups - those which have only received packets, those which have only sent packets, and those which have sent and received packets.
Local hosts (addresses) which have only received packets of almost certainly the result of remote network scans.
A large number of local hosts (addresses) which have only sent packets is unusual. It might be caused a local host attacking a remote host while randomly spoofing its source address.
Local computers are those whose IP address falls in LOCALRANGE as specified in the ipaudit-web.conf configuration file.
Most addresses send and receive packets, these are hosts involved in normal network communication.
The count of local hosts is taken every 30 minutes.