Hello, I can connect to the OpenLDAP server I want to monitor with ldapsearch: anderson@nagios:/usr/local/nagios/libexec$ ldapsearch -H ldap://xxxxx.yyyyy.edu:389 -x -b "cn=OracleContext,dc=yyyyy,dc=edu" (much data comes back) but I cannot connect with check_ldap: anderson@nagios:/usr/local/nagios/libexec$ check_ldap -H ldap://xxxxx.yyyyy.edu:389 -b "cn=OracleContext,dc=yyyyy,dc=edu" -v ldap_bind: Can't contact LDAP server (-1) Could not bind to the LDAP server What does "Can't contact LDAP server" mean in this context? It is not signalling a network connectivity problem, as seen by the success of ldapsearch. It is not signalling a hostname resolution problem; the problem symptom does not change if I use the IP address rather than the hostname. check_ldap is from nagios-plugins-release-2.2.1. Thank you for your consideration. Mark