Authentication Plugins _ldap._tcp.mem.local. 86400 IN SRV 0 100 389 ldap2.mem.local. _ldap._tcp.mem.local. 86400 IN SRV 0 100 389 ldap3.mem.local. 10.172.166.101 ldap1.mem.local 10.172.166.102 ldap2.mem.local 10.172.166.103 ldap3.mem.local 3. It may also be necessary to specify the IP address for the LDAP servers in  /etc/hosts  if the server host cannot be resolved. For example, add lines like this to the file: With the DNS configured as just described, the server-side LDAP plugin can discover the LDAP servers and tries to authenticate in all domains until authentication succeeds or there are no more servers. Windows needs no such settings as just described. Given the LDAP server host in the authentication_ldap_simple_server_host  value, the Windows LDAP library searches all domains and attempts to authenticate. • authentication_ldap_simple_server_port Command-Line Format --authentication-ldap-simple-server- port=port_num System Variable authentication_ldap_simple_server_port Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 389 Minimum Value 1 Maximum Value 32376 For simple LDAP authentication, the LDAP server TCP/IP port number. As of MySQL 8.0.14, if the LDAP port number is configured as 636 or 3269, the plugin uses LDAPS (LDAP over SSL) instead of LDAP. (LDAPS differs from  startTLS .) • authentication_ldap_simple_tls For simple LDAP authentication, whether connections by the plugin to the LDAP server are secure. If this variable is enabled, the plugin uses TLS to connect securely to the LDAP server. This variable can be set to override the default OpenLDAP TLS configuration; see LDAP Command-Line Format --authentication-ldap-simple- tls[={OFF|ON}] System Variable authentication_ldap_simple_tls Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF 1377