slapd.conf: loglevel 296 --- -1 all loging information, 0 - no logging i, 1-trace function calls; 2 -packet handling debugging i; 4- heavy trace deb..

8 - connection management
32 -search filter processing
64 - configuration file processing
128 - access control list processing
256 - statistics for connection, operations, and results
512 - statistics for results returned to clients
1024 - communication with shell backends
2048 - print entry debug information

All i is loggedusing the LOG_LEVEL4 syslog facility.
Add the following to /etc/rsyslog.conf and killall -HUP syslogd
local4.debug /var/log/slapd.log