A network operating system (NOS) is a specialized operating system for a network device such as a router, switch or firewall.
Darwin is the core Unix operating system of macOS, iOS, watchOS, tvOS, iPadOS, visionOS, and bridgeOS. It previously existed as an independent open-source operating system, first released by Apple Inc. in 2000. It is composed of code derived from NeXTSTEP, FreeBSD, other BSD operating systems, Mach, and other free software projects' code, as well as code developed by Apple.
SOCKS is an Internet protocol that exchanges network packets between a client and server through a proxy server. SOCKS5 optionally provides authentication so only authorized users may access a server. Practically, a SOCKS server proxies TCP connections to an arbitrary IP address, and provides a means for UDP packets to be forwarded. A SOCKS server accepts incoming client connection on TCP port 1080, as defined in RFC 1928.
PF is a BSD licensed stateful packet filter, a central piece of software for firewalling. It is comparable to netfilter (iptables), ipfw, and ipfilter.
IPX/SPX stands for Internetwork Packet Exchange/Sequenced Packet Exchange. IPX and SPX are networking protocols used initially on networks using the Novell NetWare operating systems. They also became widely used on networks deploying Microsoft Windows LANS, as they replaced NetWare LANS, but are no longer widely used. IPX/SPX was also widely used prior to and up to Windows XP, which supported the protocols, while later Windows versions do not, and TCP/IP took over for networking.
XNU is the computer operating system (OS) kernel developed at Apple Inc. since December 1996 for use in the Mac OS X operating system and released as free and open-source software as part of the Darwin OS, which in addition to macOS is also the basis for the Apple TV Software, iOS, iPadOS, watchOS, visionOS, and tvOS OSes.
In computer networking, port forwarding or port mapping is an application of network address translation (NAT) that redirects a communication request from one address and port number combination to another while the packets are traversing a network gateway, such as a router or firewall. This technique is most commonly used to make services on a host residing on a protected or masqueraded (internal) network available to hosts on the opposite side of the gateway, by remapping the destination IP address and port number of the communication to an internal host.
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.
An application firewall is a form of firewall that controls input/output or system calls of an application or service. It operates by monitoring and blocking communications based on a configured policy, generally with predefined rule sets to choose from. The two primary categories of application firewalls are network-based and host-based.
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.
In Unix-based computer operating systems, init is the first process started during booting of the operating system. Init is a daemon process that continues running until the system is shut down. It is the direct or indirect ancestor of all other processes and automatically adopts all orphaned processes. Init is started by the kernel during the booting process; a kernel panic will occur if the kernel is unable to start it, or it should die for any reason. Init is typically assigned process identifier 1.
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.
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version of FreeBSD was released in 1993 developed from 386BSD and the current version runs on x86, ARM, PowerPC and RISC-V processors. The project is supported and promoted by the FreeBSD Foundation.
Tinc is an open-source, self-routing, mesh networking protocol and software implementation used for compressed and encrypted virtual private networks. It was started in 1998 by Guus Sliepen, Ivo Timmermans, and Wessel Dankers, and released as a GPL-licensed project.
OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. The OpenBSD project emphasizes portability, standardization, correctness, proactive security, and integrated cryptography.
SoftEther VPN is free open-source, cross-platform, multi-protocol VPN client and VPN server software, developed as part of Daiyuu Nobori's master's thesis research at the University of Tsukuba. VPN protocols such as SSL VPN, L2TP/IPsec, OpenVPN, and Microsoft Secure Socket Tunneling Protocol are provided in a single VPN server. It was released using the GPLv2 license on January 4, 2014. The license was switched to Apache License 2.0 on January 21, 2019.
WireGuard is a communication protocol and free and open-source software that implements encrypted virtual private networks (VPNs), and was designed with the goals of ease of use, high speed performance, and low attack surface. It aims to be smaller and better performing than IPsec and OpenVPN, two common tunneling protocols. The WireGuard protocol passes traffic over UDP.
