Centralized authentication security

        Configure an NIS server to provide directory services
        Configure Kerberos to provide user authentication
        Configure NFSv4 server
        Configure a network client to use NIS for directory information
        Configure a network client to use Kerberos for authentication
        Configure a network client to mount an NFSv4 export
        Configure r-clients (rlogin, rcp, etc.) and telnet to use Kerberos

Network Services Security

        Use xinetd and TCP wrappers to restrict access to network services
        Configure Postfix and Sendmail to:
            Filter mail based on message characteristics
            Use TLS for secure communication
            Use the Real-time Blackhole List (RBL) via DNS
        Configure POP/IMAP to use SSL/TLS for secure communication
        Configure the following aspects of DNS:
            Master domain
            Slave domain
            Views
            Forwarders
            Blackhole lists (RBL)
            TSIG
        Use GPG tools to:
            Generate key pairs
            Sign documents
            Encrypt documents
            Decrypt documents
            Verify document signatures
        Configure a certificate authority (CA) and sign certificate requests
        Configure httpd to use an SSL certificate signed by a certifying authority
        Configure httpd to use passwords and/or network location to restrict access to content
        Configure FTP security to:
            Support FTP only users
            Implement host-based access restrictions