Implementing SSL / TLS Using Cryptography and PKI
SSH, The Secure Shell: The Definitive Guide: The Definitive Guide
Kerberos: The Definitive Guide
Secure Programming Cookbook for C and C++: Recipes for Cryptography, Authentication, Input Validation & More
DNS and BIND: Help for System Administrators
LDAP System Administration: Putting Directories to Work
sed & awk: UNIX Power Tools (Nutshell Handbooks)
SSH Mastery: OpenSSH, PuTTY, Tunnels and Keys (IT Mastery Book 12)
TCP/IP Network Administration: Help for Unix System Administrators
Active Directory: Designing, Deploying, and Running Active Directory