System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP)

Chapter 17 LDAP Troubleshooting (Reference)

This chapter describes configuration problems and suggests solutions for resolving them.

Monitoring Client Status

The following sections show various commands to help determine the state of the LDAP client environment. Also see the man pages for additional information about the options that can be used.

Verifying ldap_cachemgr Is Running

The ldap_cachemgr daemon must be running and functioning correctly at all times. Otherwise, the system doesn't work. There are two ways to check if ldap_cachemgr is running.

Checking the Current Profile Information

Become superuser and run ldapclient with the -l option.

# ldapclient -l
NS_LDAP_BINDDN= cn=proxyagent,ou=profile,dc=west,dc=example,dc=com
NS_LDAP_BINDPASSWD= {NS1}4a3788e8c053424f
NS_LDAP_SEARCH_BASEDN= dc=west,dc=example,dc=com
NS_LDAP_AUTH= simple
NS_LDAP_SERVICE_SEARCH_DESC= passwd:ou=people,?sub
NS_LDAP_SERVICE_SEARCH_DESC= group:ou=group,dc=west,dc=example,dc=com?one

Currently the /var/ldap files are in ASCII format. Because the files could change to binary at some time, concatenating the files would cause problems. ldapclient list is the supported method for accessing this information.

Verifying Basic Client-Server Communication

The best way to show that your client is talking to the LDAP server is with the ldaplist command. Using ldaplist with no arguments dumps all the containers on the server. This works as long as the containers exist, and do not have to be populated.

If the first step works, you can try ldaplist passwd username or ldaplist hosts hostname but if they contain lots of data you might want to pick a less populated service, or pipe them to head or more.

Checking Server Data From a Non-Client Machine

Most of the commands in the previous sections assume you already have created an LDAP client. If you have not created a client and want to check the data on the server, use the ldapsearch command. The following example lists all of the containers.

# ldapsearch -h server1 -b "dc=west,dc=example,dc=com" -s one "objectclass=*"

Configuration Problems and Solutions

The following sections describe LDAP configuration problems and suggests solutions to the problems.

Unresolved Hostname

The Solaris operating environment LDAP client back end returns fully qualified host names for host lookups, such as host names returned by gethostbyname() and getaddrinfo(). If the name stored is qualified, that is, contains at least one dot, the client returns the name as is. For example, if the name stored is hostB.eng, the returned name is hostB.eng.

If the name stored in the LDAP directory is not qualified (it does not contain a dot), the client back end appends the domain part to the name. For example, if the name stored is hostA, the returned name is hostA.domainname.

Unable to Reach Systems in the LDAP Domain Remotely

If the DNS domain name is different from the LDAP domain name, then the LDAP naming service cannot be used to serve host names unless the host names are stored fully qualified.

Login Does Not Work

LDAP clients use the PAM modules for user authentication during login. When using the standard UNIX PAM module, the password is read from the server and checked on the client side. This can fail due to one of the following reasons:

  1. ldap is not used by the passwd service in the /etc/nsswitch.conf file.

  2. The user's userPassword attribute on the server list is not readable by the proxy agent. You need to allow at least the proxy agent to read the password because the proxy agent returns it to the client for comparison. pam_ldap does not require read access to the password.

  3. The proxy agent might not have the correct password.

  4. The entry does not have the shadowAccount object class.

  5. No password is defined for the user.

    When you use ldapaddent, you must use the -p option to ensure that the password is added to the user entry. If you use ldapaddent without the -p option, the user's password is not stored in the directory unless you also add the /etc/shadow file by using ldapaddent.

  6. No LDAP servers are reachable.

    Check the status of the servers.

    # /usr/lib/ldap/ldap_cachemgr -g
  7. pam.conf is configured incorrectly.

  8. The user is not defined in the LDAP namespace.

  9. NS_LDAP_CREDENTIAL_LEVEL is set to anonymous for pam_unix, and userPassword is not available to anonymous users.

  10. The password is not stored in crypt format.

  11. If pam_ldap is configured to support password management, login failure could be the result of one of the following:

    • The user's password has expired.

    • The user's account is locked out due to too many failed login attempts.

    • The user's account has been deactivated by the administrator.

Lookup Too Slow

The LDAP database relies on indexes to improve search performance. A major performance degradation occurs when indexes are improperly configured. The documentation includes a common set of attributes that should be indexed. You can also add your own indexes to improve performance at your site.

ldapclient Cannot Bind to Server

ldapclient failed to initialize the client when using the -p option. Possible reasons for failure include the following:

  1. The incorrect domain name was specified on the command line.

  2. The nisDomain attribute is not set in the DIT to represent the entry point for the specified client domain.

  3. Access control information is not set up properly on the server, thus disallowing anonymous search in the LDAP database.

  4. An incorrect server address passed to the ldapclient command. Use ldapsearch to verify the server address.

  5. An incorrect profile name passed to the ldapclient command. Use ldapsearch to verify the profile name in the DIT.

  6. Use snoop on the client's network interface to see what sort of traffic is going out, and determine to which server it is talking.

Using ldap_cachemgr for Debugging

Using ldap_cachemgr with the -g option can be a useful way to debug, as you can view the current client configuration and statistics. For example,

# ldap_cachemgr -g

would print current configuration and statistics to standard output, including the status of all LDAP servers, as mentioned previously. Note that you do not need to become super user to execute this command.

ldapclient Hangs During Setup

If the ldapclient command hangs, pressing Ctrl-C will exit after restoring the previous environment. If this happens, check with the server administrator to ensure that the server is running.

Also check the server list attributes in either the profile or from the command line and make sure that the server information is correct.