IPwatchD is a simple daemon that analyses all incoming ARP packets in order to detect IP conflicts.
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
configuration mode IPwatchD detects all network interfaces automatically and sets passive protection mode for them. In
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
protection mode IPwatchD protects your host before IP takeover by answering gratuitous ARP requests received from conflicting system. In
protection mode it just records information about IP conflict through standard syslog interface.