GoboLinux is an open source operating system whose most prominent feature is a reorganization of the traditional Linux file system. Rather than following the Filesystem Hierarchy Standard like most Unix-like systems, each program in a GoboLinux system has its own subdirectory tree, where all of its files may be found. Thus, a program "Foo" has all of its specific files and libraries in /Programs/Foo, under the corresponding version of this program at hand. For example, the commonly known GCC compiler suite version 8.1.0, would reside under the directory /Programs/GCC/8.1.0.
Unix security refers to the means of securing a Unix or Unix-like operating system. A secure environment is achieved not only by the design concepts of these operating systems, but also through vigilant user and administrative practices.
GNU GRUB is a boot loader package from the GNU Project. GRUB is the reference implementation of the Free Software Foundation's Multiboot Specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system's partitions.
OpenVPN is a virtual private network (VPN) system that implements techniques to create secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It implements both client and server applications.
IPFilter is an open-source software package that provides firewall services and network address translation (NAT) for many Unix-like operating systems. The author and software maintainer is Darren Reed. IPFilter supports both IPv4 and IPv6 protocols, and is a stateful firewall.
iptables is a user-space utility program that allows a system administrator to configure the IP packet filter rules of the Linux kernel firewall, implemented as different Netfilter modules. The filters are organized in different tables, which contain chains of rules for how to treat network traffic packets. Different kernel modules and programs are currently used for different protocols; iptables applies to IPv4, ip6tables to IPv6, arptables to ARP, and ebtables to Ethernet frames.
Netfilter is a framework provided by the Linux kernel that allows various networking-related operations to be implemented in the form of customized handlers. Netfilter offers various functions and operations for packet filtering, network address translation, and port translation, which provide the functionality required for directing packets through a network and prohibiting packets from reaching sensitive locations within a network.
Shorewall is an open source firewall tool for Linux that builds upon the Netfilter (iptables/ipchains) system built into the Linux kernel, making it easier to manage more complex configuration schemes by providing a higher level of abstraction for describing rules using text files.
DTrace is a comprehensive dynamic tracing framework originally created by Sun Microsystems for troubleshooting kernel and application problems on production systems in real time. Originally developed for Solaris, it has since been released under the free Common Development and Distribution License (CDDL) in OpenSolaris and its descendant illumos, and has been ported to several other Unix-like systems.
Linux IP Firewalling Chains, normally called ipchains, is free software to control the packet filter or firewall capabilities in the 2.2 series of Linux kernels. It superseded ipfirewall, but was replaced by iptables in the 2.4 series. Unlike iptables, ipchains is stateless.
Firestarter is a personal firewall tool that uses the Netfilter (iptables/ipchains) system built into the Linux kernel. It has the ability to control both inbound and outbound connections. Firestarter provides a graphical interface for configuring firewall rules and settings. It provides real-time monitoring of all network traffic for the system. Firestarter also provides facilities for port forwarding, internet connection sharing and DHCP service.
ipfirewall or ipfw is a FreeBSD IP, stateful firewall, packet filter and traffic accounting facility. Its ruleset logic is similar to many other packet filters except IPFilter. ipfw is authored and maintained by FreeBSD volunteer staff members. Its syntax enables use of sophisticated filtering capabilities and thus enables users to satisfy advanced requirements. It can either be used as a loadable kernel module or incorporated into the kernel; use as a loadable kernel module where possible is highly recommended. ipfw was the built-in firewall of Mac OS X until Mac OS X 10.7 Lion in 2011 when it was replaced with the OpenBSD project's PF. Like FreeBSD, ipfw is open source. It is used in many FreeBSD-based firewall products, including m0n0wall and FreeNAS. A port of an early version of ipfw was used since Linux 1.1 as the first implementation of firewall available for Linux, until it was replaced by ipchains. A modern port of ipfw and the dummynet traffic shaper is available for Linux and Microsoft Windows. wipfw is a Windows port of an old (2001) version of ipfw.
Sentry Firewall is a free open-source network firewall Linux distribution that was first published in 2001 and has been the subject of multiple magazine reviews. The distribution is particularly notable because it consists solely of a bootable CD-ROM that is designed to be used in a computer with no hard disk. Configuration information is retrieved at boot time by automatically searching on an attached floppy disk drive, USB flash memory drive, or another server on the local network willing to provide the configuration.
Fail2ban is an intrusion prevention software framework that protects computer servers from brute-force attacks. Written in the Python programming language, it is able to run on POSIX systems that have an interface to a packet-control system or firewall installed locally, for example, iptables or TCP Wrapper.
The arptables computer software utility is a network administrator's tool for maintaining the Address Resolution Protocol (ARP) packet filter rules in the Linux kernel firewall modules.
nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames. It has been available since Linux kernel 3.13 released on 19 January 2014.
cgroups is a Linux kernel feature that limits, accounts for, and isolates the resource usage of a collection of processes.
firewalld is a firewall management tool for Linux operating systems. It provides firewall features by acting as a front-end for the Linux kernel's netfilter framework. firewalld's current default backend is nftables. Prior to v0.6.0, iptables was the default backend. Through its abstractions, firewalld acts as an alternative to nft and iptables command line programs. The name firewalld adheres to the Unix convention of naming system daemons by appending the letter "d".
CBL-Mariner is a free and open-source, Linux distribution that Microsoft has developed. It is the base container OS for Microsoft Azure services and the graphical component of WSL 2.
