Today's datacenters embrace various platforms in conjunction with z/OS. Kerberos can provide an integrated approach to enterprise-wide user authentication and therefore access control using RACF/ACF2/Top Secret. It is de-facto on LINUX, UNIX, Windows and its use here is widespread. It is already implemented on z/OS for DB2, WAS, FTP, TELNET and others. In this presentation you will hear real life user experiences when implementing DB2 Connect to DB2 z/OS authentication. It also addresses authentication where the client is on z/OS and wishes to authenticate using Kerberos against LINUX, UNIX and Windows. Some case studies are included where vendor products are not themselves Kerberos aware and Kerberos authentication can be leveraged transparently of the vendor.