man nss_ldap and man ldap.conf. The parameters you may be interested in : bind_policy nss_connect_policy bind_timelimit 2010/2/3 Majian <jiannma(a)gmail.com&gt;:

Thank for all suggestions . But the problem have not solved yet ~ Maybe it is the LDAP cache problem ~ I tried to google "ldap cache " ,The message is the following : " LDAP cache This section contains performance tuning tasks that are not normally recommended; however, there may be some environments where these performance tuning tasks are useful. The LDAP cache is more efficient in memory usage and faster than the DB2 cache, yet not as efficient as the Tivoli Access Manager credential cache. Disadvantages to the LDAP cache are that it becomes invalidated on most update operations and can take a long time to load. The environments that benefit the most from LDAP caching are those with small registry sizes and few updates. Keep in mind that increasing the LDAP cache size can cause the slapd or the ibmslapd process memory size to exceed system limits. For information about increasing these limits, see Tuning process memory size limits. ....." On Thu, Feb 4, 2010 at 12:22 AM, Morris, Patrick <patrick.morris(a)hp.com&gt;wrote: