Controls how the search interface will log search request IP addresses via three settings:
log request IP addresses as normal
log a unique one-way hash of each incoming request IP address
do not log request IP addresses
Some of the query reports rely on the IP addresses to extract information about users (especially the "Top Searchers" and "Top Searchers by Country" reports). If the IP address is not logged or is logged as a hash, these reports will display "Unknown".