Draft Document for Review February 7, 2020 3:15 pm 8464ch02_Architecture.fm 2.3.17 Security identification by using Lightweight Directory Access Protocol 2.3.18 Grid Resiliency functions  2.3.19 Service preparation mode  2.3.20 Service mode Previous implementations are based on Tivoli System Storage™ Productivity Center to  authenticate users to a client’s Lightweight Directory Access Protocol (LDAP) server.  Beginning with Release 3.0 of Licensed Internal Code (LIC), the TS7700 clusters and  TS3000 System Console (TS3000 TSSC) include native support for an LDAP. After LDAP is enabled, the TS7700 MI is controlled by the LDAP server. Also, the local  actions that are run by the IBM SSR are secured by the LDAP server. All IBM standard users  can no longer access the system without a valid LDAP user ID and password. You must have  a valid account in the LDAP server and appropriate roles defined to log in to the TS7700. If your LDAP server is not available, you cannot interact with TS7700 (not with IBM SSR or an  operator). Important:  Create at least one external authentication policy for IBM SSRs before a  service event. IBM RACFfi can also be used to control the access when LDAP is contained within IBM Z,  which means that users are defined to RACF and verified through a RACF database. Roles  and profiles still must be maintained because the RACF database provides password  authentication only. When enabling LDAP, two optional settings in the MI enablement page for LDAP allow a local  SSR and/or IBM second-level remote support bypass LDAP.  With R4.1.2, a new function to improve the resiliency of a grid was introduced. This function  allows a cluster to automatically reboot if an unrecoverable failure of a cluster in a grid occurs.  Peers can start the reboot on behalf of the cluster and clusters can self-reboot (local fence) if  needed as well, including stand-alone clusters that do not exist in a grid. For more information, see  IBM TS7700 Series Grid Resiliency Improvements User’s Guide ,  WP102742. This function is available in a multi-cluster grid only. This function is available in a multi-cluster grid only. 58  IBM TS7700 Release 5.0 Guide