A network operating system (NOS) is a specialized

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

for a network device such as a router,

switch In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type o ...

or firewall. Historically operating systems with networking capabilities were described as network operating systems, because they allowed personal computers (PCs) to participate in

computer network A computer network is a collection of communicating computers and other devices, such as printers and smart phones. In order to communicate, the computers and devices must be connected by wired media like copper cables, optical fibers, or b ...

s and shared file and printer access within a local area network (LAN). This description of operating systems is now largely historical, as common operating systems include a

network stack The protocol stack or network stack is an implementation of a computer networking protocol suite or protocol family. Some of these terms are used interchangeably but strictly speaking, the ''suite'' is the definition of the communication protoc ...

to support a client–server model.

Key Functions

Network Operating Systems (NOS) are responsible for managing various network activities. Key functions include creating and managing user accounts, controlling access to resources such as files and printers, and facilitating communication between devices. NOS also monitors network performance, addresses issues, and manages resources to ensure efficient and secure operation of the network.

History

Packet switching In telecommunications, packet switching is a method of grouping Data (computing), data into short messages in fixed format, i.e. ''network packet, packets,'' that are transmitted over a digital Telecommunications network, network. Packets consi ...

networks were developed to share hardware resources, such as a

mainframe computer A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterprise ...

, a

printer Printer may refer to: Technology * Printer (publishing), a person * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer (fl. c. 1940), Indian journalist and activist * James Printer (1640 ...

or a large and expensive

hard disk A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, pla ...

. Historically, a network operating system was an

for a computer which implemented network capabilities. Operating systems with a

allowed

personal computer A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...

s to participate in a client-server architecture in which a

server Server may refer to: Computing *Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients. Role * Waiting staff, those who work at a restaurant or a bar attending custome ...

enables multiple clients to share resources, such as

printers Printer may refer to: Technology * Printer (publishing), a person * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer (fl. c. 1940), Indian journalist and activist * James Printer (1 ...

. These limited client/server networks were gradually replaced by

Peer-to-peer Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network, forming a peer-to-peer network of Node ...

networks, which used networking capabilities to share resources and files located on a variety of computers of all sizes. A peer-to-peer network sets all connected computers equal; they all share the same abilities to use resources available on the network. Today,

distributed computing Distributed computing is a field of computer science that studies distributed systems, defined as computer systems whose inter-communicating components are located on different networked computers. The components of a distributed system commu ...

and groupware applications have become the norm. Computer operating systems include a networking stack as a matter of course. During the 1980s the need to integrate dissimilar computers with network capabilities grew and the number of networked devices grew rapidly. Partly because it allowed for multi-vendor

interoperability Interoperability is a characteristic of a product or system to work with other products or systems. While the term was initially defined for information technology or systems engineering services to allow for information exchange, a broader de ...

, and could route packets globally rather than being restricted to a single building, the Internet protocol suite became almost universally adopted in network architectures. Thereafter, computer operating systems and the

firmware In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computer, computing machinery. It includes the study and experimentation of algorithmic processes, and the development of both computer hardware, h ...

of network devices tended to support Internet protocols.

Network device operating systems

Network operating systems can be embedded in a router or hardware firewall that operates the functions in the

network layer In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate Router (computing), routers. Functions The network layer provides t ...

(

layer 3 In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers. Functions The network layer provides the means of transf ...

). Notable network operating systems include:

Proprietary network operating systems

Cisco IOS The Internetworking Operating System (IOS) is a family of proprietary network operating systems used on several router and network switch models manufactured by Cisco Systems Cisco Systems, Inc. (using the trademark Cisco) is an American ...

, a family of network operating systems used on

Cisco Systems Cisco Systems, Inc. (using the trademark Cisco) is an American multinational corporation, multinational digital communications technology conglomerate (company), conglomerate corporation headquartered in San Jose, California. Cisco develops, m ...

routers and

network switch A network switch (also called switching hub, bridging hub, Ethernet switch, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destinat ...

es. (Earlier switches ran the Catalyst operating system, or

CatOS Catalyst is the brand for a variety of network switches, wireless controllers, and wireless access points sold by Cisco Systems. While commonly associated with Ethernet switches, a number of different types of network interfaces have been availa ...

) * RouterOS by

MikroTik MikroTik (officially SIA "Mikrotīkls") is a Latvian network equipment manufacturing company. MikroTik develops and sells Wired communication, wired and Wireless communication, wireless network Router (computing), routers, network switches, Wirele ...

ZyNOS ZyNOS is the proprietary operating system used on network devices made by Zyxel Communications. The name is a contraction of Zyxel and Network Operating System (NOS). History Zyxel first introduced ZyNOS in 1998. Versions Zyxel released ZyNO ...

, used in network devices made by ZyXEL

FreeBSD, NetBSD, OpenBSD, and Linux-based operating systems

Cisco NX-OS NX-OS is a network operating system for the Nexus-series Ethernet switches and MDS-series Fibre Channel storage area network switches made by Cisco Systems. It evolved from the Cisco operating system SAN-OS, originally developed for its MDS sw ...

, IOS XE, and

IOS XR IOS XR is a release train of Cisco Systems' widely deployed Internetwork Operating System (IOS), used on their high-end Network Convergence System (NCS) and carrier-grade routers such as the ASR 9000 series and Carrier Routing System ser ...

; families of network operating systems used across various Cisco Systems device including the Cisco Nexus and Cisco ASR platforms *

Junos OS Junos OS (also known as Juniper Junos, Junos and JUNOS) is a FreeBSD-based, and later also Linux-based, network operating system used in Juniper Networks routing, switching and security devices. Versions Junos OS was first made available on 7 J ...

; a network operating system that runs on

Juniper Networks Juniper Networks, Inc. is an American multinational corporation headquartered in Sunnyvale, California. The company develops and markets networking products, including Router (computing), routers, Network switch, switches, network management so ...

platforms * Cumulus Linux distribution, which uses the full

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are ...

stack of Linux *

DD-WRT DD-WRT is Linux-based firmware for wireless routers and access points. Originally designed for the Linksys WRT54G series, it now runs on a wide variety of models. DD-WRT is one of a handful of third-party firmware projects designed to replace ...

, a Linux kernel-based firmware for wireless routers and access points as well as low-cost networking device platforms such as the

Linksys Linksys Holdings, Inc., is an American brand of data networking hardware products mainly sold to home users and small businesses. It was founded in 1988 by the couple Victor Tsao, Victor and Janie Tsao, both Taiwanese immigrants to the United St ...

WRT54G The Linksys WRT54G Wi-Fi series is a series of Wi-Fi–capable residential gateways marketed by Linksys, a subsidiary of Cisco, from 2003 until acquired by Belkin in 2013. A ''residential gateway'' connects a local area network (such as a home net ...

Dell Networking Operating System DNOS or Dell Networking Operating System is a network operating system running on switches from Dell Networking. It is derived from either the PowerConnect OS (DNOS 6.x) or Force10 OS/ FTOS (DNOS 9.x) and will be made available for the 10G and fas ...

; DNOS9 is

NetBSD NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to ...

based, while OS10 uses the

Linux kernel The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

Extensible Operating System Arista Networks, Inc. (formerly Arastra) is an American computer networking company headquartered in Santa Clara, California. The company designs and sells multilayer network switches to deliver software-defined networking (SDN) for large datacent ...

runs on switches from Arista and uses an unmodified Linux kernel *

ExtremeXOS ExtremeXOS is the software or the network operating system used in newer Extreme Networks network switches.. It is Extreme Networks second generation operating system after the VxWorks based ExtremeWare operating system. ExtremeXOS is based on th ...

(EXOS), used in network devices made by

Extreme Networks Extreme Networks, Inc. is an American networking company based in Morrisville, North Carolina. Extreme Networks designs, develops, and manufactures wired and wireless network infrastructure equipment and develops the software for network managem ...

FTOS FTOS or Force10 Operating System is the firmware family used on Force10 Ethernet switches. It has a similar functionality as Cisco's NX-OS or Juniper's Junos. FTOS 10 is running on Debian. As part of a re-branding strategy of Dell FTOS will be ...

(Force10 Operating System), the

family used on

Force10 Dell Force10 (formerly nCore Networks, Force10 Networks), was a United States company that developed and marketed 10 Gigabit and 40 Gigabit Ethernet switches for computer networking to corporate, educational, and governmental customers. It had ...

Ethernet switches *

ONOS fa:کاربر:CSF-404/ONOS :fa:کاربر:CSF-404/ONOS, The ONOS (Open Network Operating System) project is an open source community hosted by The Linux Foundation. The goal of the project is to create a software-defined networking (SDN) operatin ...

, an open source SDN operating system (hosted by

Linux Foundation The Linux Foundation (LF) is a non-profit organization established in 2000 to support Linux development and open-source software projects. Background The Linux Foundation started as Open Source Development Labs in 2000 to standardize and prom ...

) for communications service providers that is designed for scalability, high performance and high availability. *

OpenBSD OpenBSD is a security-focused operating system, security-focused, free software, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by fork (software development), forking NetBSD ...

, an open source operating system which includes its own implementations of

BGP Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous system (Internet), autonomous systems (AS) on the Internet. BGP is classified as a path-vect ...

RPKI Resource Public Key Infrastructure (RPKI), also known as Resource Certification, is a specialized public key infrastructure (PKI) framework to support improved security for the Internet's BGP routing infrastructure. RPKI provides a way to connect ...

OSPF Open Shortest Path First (OSPF) is a routing protocol for Internet Protocol (IP) networks. It uses a link state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs), operating within a single autonomous sys ...

MPLS Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints, the labels identi ...

VXLAN Virtual eXtensible LAN (VXLAN) is a network virtualization technology that uses a VLAN-like encapsulation technique to encapsulate OSI model, OSI layer 2 Ethernet frames within layer 4 User Datagram Protocol, UDP datagrams, using 4789 as the defau ...

, and other

IETF The Internet Engineering Task Force (IETF) is a standards organization for the Internet standard, Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster ...

standardized networking protocols, as well as firewall ( PF) and load-balancing functionality. *

OpenWrt OpenWrt (from ''open wireless router'') is an open-source project for embedded operating systems based on Linux kernel, Linux, primarily used on Embedded system, embedded devices to Router (computing), route network traffic. The main components ...

used to route IP packets on

embedded devices An embedded system is a specialized computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is emb ...

pfSense pfSense is a firewall/ router computer software distribution based on FreeBSD. The open source pfSense Community Edition (CE) and pfSense Plus is installed on a physical computer or a virtual machine In computing, a virtual machine (VM) is ...

, a fork of

M0n0wall m0n0wall was an embedded firewall (networking), firewall distribution of FreeBSD, one of the Berkeley Software Distribution, BSD operating system descendants. It provided a small image which could be put on flash memory, Compact Flash cards as w ...

, which uses PF *

OPNsense __NOTOC__ OPNsense is an open source, FreeBSD-based firewall and routing software developed by Deciso, a company in the Netherlands that makes hardware and sells support packages for OPNsense. Launched in 2015, it is a Fork_(software_development) ...

, a fork of pfSense *

SONiC Sonic or Sonics may refer to: Companies *Sonic Drive-In, an American drive-in, fast-food restaurant chain * Sonic (ISP), an Internet provider CLEC, serving more than 100 California communities * Sonic Foundry, a computer software company whic ...

, a Linux-based network operating system developed by

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

* VyOS, an open source fork of the Vyatta routing package

References