What command must be run to check a configuration for an LDAP server while troubleshooting?

The command needed to check a configuration for an LDAP server while troubleshooting is slaptest. This utility is specifically designed to verify the correctness of the configuration files for the LDAP server (OpenLDAP) without actually starting the server. It checks for syntax errors and other issues that could prevent the LDAP service from functioning properly.

Using slaptest allows administrators to ensure that the configuration is valid before attempting to start the LDAP server, which can help in diagnosing problems quickly. If there are errors in the configuration files, slaptest will output relevant messages that indicate what needs to be corrected, thus facilitating efficient troubleshooting.

In contrast, while ldapsearch is used to search the LDAP database and ldapadd is employed to add entries to the LDAP directory, neither of these commands is meant for verifying configuration changes. The slapd command, when executed with the -d option, enables debugging information during runtime but does not validate configuration files before the server starts. This makes slaptest the most appropriate choice for configuration verification.