Default configuration file uses "automatic configuration mode" with "passive protection mode" and it should be the best option for most systems.
Configuration mode applies to the daemon instance and it specifies how the list of network interfaces that should be monitored will be obtained. In automatic configuration mode IPwatchD detects all network interfaces automatically and sets passive protection mode for them. In manual configuration mode it is up to the system administrator to specify list of interfaces and protection modes in configuration file.
Protection mode specifies the action that will be performed when IP conflict is detected. In active protection mode IPwatchD protects your host before IP takeover by answering gratuitous ARP requests received from conflicting system. In passive protection mode it just records information about IP conflict through standard syslog interface.
IPwatchD also supports execution of user defined scripts. See ipwatchd.conf(5) and ipwatchd-script(1) for more details.