Clonezilla is a partition or disk cloning tool similar to Symantec Ghost. It saves and restores only blocks in use on the hard drive if the file system is supported. For unsupported file systems, dd is used instead. It has been used to clone a 5 GB system to 40 clients in about 10 minutes.
Lynis is an auditing and hardening tool for Unix derivatives like Linux/BSD/Solaris. It scans systems to detect software and security issues. Besides security-related information, it will also scan for general system information, installed packages, and possible configuration mistakes. The software is aimed at assisting automated auditing, software patch management, and vulnerability and malware scanning of Unix-based systems.
Diskless Remote Boot in Linux (DRBL) provides a diskless or systemless environment for client machines. It works on Debian, Mandriva, Red Hat, Fedora, and SuSE. Unlike LTSP, it uses distributed hardware resources and makes it possible for clients to fully access local hardware. It also includes Clonezilla, a partitioning and disk cloning utility similar to Symantec Ghost.
nss-pam-ldapd is a Name Service Switch module and Pluggable Authentication Module using an LDAP server. It allows your LDAP server to provide user account, group, host name, alias, netgroup, and almost any other information that you would normally get from /etc flat files or NIS, and allows you to do authentication to an LDAP server.
The Mandos system allows computers to have encrypted root file systems and at the same time be capable of remote or unattended reboots. The computers run a small client program in the initial RAM disk environment which will communicate with a server over a network. All network communication is encrypted using TLS. The clients are identified by the server using an OpenPGP key that is unique to each client. The server sends the clients an encrypted password. The encrypted password is decrypted by the clients using the same OpenPGP key, and the password is then used to unlock the root file system.
MailScanner is an email virus scanner, vulnerability protector, and spam tagger. It supports the Postfix, Sendmail, Exim, Qmail, and ZMailer MTAs, and the Sophos, McAfee, F-Prot, F-Secure, CommandAV, InoculateIT, Inoculan, eTrust, Kaspersky, Nod32, AntiVir, BitDefender, RAV, Panda, DrWeb, ClamAV, and other anti-virus scanners. It uses SpamAssassin for highly successful spam identification, and is designed to handle denial of service attacks. It will detect password-protected zip files and apply filename checking to their contents. It is very easy to install, requires no changes at all to your sendmail.cf file, is designed to be lightweight, and won't grind your mail system to a halt with its load. It can be integrated into any email system, regardless of the software in use.
Arno's IPTABLES Firewall Script is a secure stateful firewall for both single and multi-homed machines. It supports NAT and SNAT, port forwarding, ADSL ethernet modems with both static and dynamically assigned IPs, MAC address filtering, stealth port scan detection, DMZ support, protection against SYN/ICMP flooding, experimental IPv6 support, multi-interface/aliased-IP support, and extensive user definable logging with rate limiting to prevent log flooding. It has plugin support to add extra features (like SSH Brute Force protection and (Racoon) IPSEC support). It is easy to configure and highly customizable. A filter script that makes your firewall log more readable is also included.
FireHOL a simple yet powerful way to configure stateful iptables firewalls. It can be used for almost any purpose, including control of any number of internal/external/virtual interfaces, control of any combination of routed traffic, setting up DMZ routers and servers, and all kinds of NAT. It provides strong protection (flooding, spoofing, etc.), transparent caches, source MAC verification, blacklists, whitelists, and more. Its goal is to be completely abstracted and powerful but also easy to use, audit, and understand.