NX-OS is a network operating system

Network operating system

A networking operating system , also referred to as the Dialoguer, is the software that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions...

 designed by Cisco Systems

Cisco Systems

Cisco Systems, Inc. is an American multinational corporation headquartered in San Jose, California, United States, that designs and sells consumer electronics, networking, voice, and communications technology and services. Cisco has more than 70,000 employees and annual revenue of US$...

 for their own Nexus series Ethernet switches and MDS series Fibre Channel storage area network switches. NX-OS is designed to support high performance, high reliability server access switches used in the data center

Data center

A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems...

. NX-OS evolved from the Cisco MDS operating system, SAN-OS. SAN-OS was originally developed for the MDS line of switches.

It is based on MontaVista Software embedded Linux

Embedded Linux

Embedded Linux is the use of Linux in embedded computer systems such as mobile phones, personal digital assistants, media players, set-top boxes, and other consumer electronics devices, networking equipment, machine control, industrial automation, navigation equipment and medical instruments...

. It is inter-operable with other Cisco operating systems. It runs on both the Nexus and MDS product lines by Cisco.

NX-OS command-line interface

Command-line interface

A command-line interface is a mechanism for interacting with a computer operating system or software by typing commands to perform specific tasks...

 is IOS

Cisco IOS

Cisco IOS is the software used on the vast majority of Cisco Systems routers and current Cisco network switches...

-like. However, some features need to be first explicitly enabled before configuring.

Features

• FCIP Fibre Channel over IP
• FCoE Fibre Channel over Ethernet (Nexus 5000 Only/newer 7000 linecards)
• iSCSI
  ISCSI
  In computing, iSCSI , is an abbreviation of Internet Small Computer System Interface, an Internet Protocol -based storage networking standard for linking data storage facilities. By carrying SCSI commands over IP networks, iSCSI is used to facilitate data transfers over intranets and to manage...
  
  
• IPSec
  IPsec
  Internet Protocol Security is a protocol suite for securing Internet Protocol communications by authenticating and encrypting each IP packet of a communication session...
  
  
• Scheduling
• NPIV
  NPIV
  N_Port ID Virtualization or NPIV is a Fibre Channel facility allowing multiple N_Port IDs to share a single physical N_Port. This allows multiple Fibre Channel initiators to occupy a single physical port, easing hardware requirements in Storage Area Network design, especially where virtual SANs...
  
   Nx port Id Virtualization
• IVR (Inter-VSAN Routing)
• VSAN
  VSAN
  In computer networking, a virtual storage area network is a collection of ports from a set of connected Fibre Channel switches, that form a virtual fabric. Ports within a single switch can be partitioned into multiple VSANs, despite sharing hardware resources...
  
  
• Zoning (Hard zoning)
• Callhome
• CFS Cisco Fabric Services (Distributed configuration)
• SSH
  Secure Shell
  Secure Shell is a network protocol for secure data communication, remote shell services or command execution and other secure network services between two networked computers that it connects via a secure channel over an insecure network: a server and a client...
  
   and Telnet
  TELNET
  Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection...
  
  
• SME Storage Media Encryption
• Port Channels
• Cisco Data Mobility Manager
• Fibre Channel Write Acceleration
• FICON
  FICON
  FICON is the IBM proprietary name for the ANSI FC-SB-3 Single-Byte Command Code Sets-3 Mapping Protocol for Fibre Channel protocol. It is a FC layer 4 protocol used to map both IBM’s antecedent channel-to-control-unit cabling infrastructure and protocol onto standard FC services and infrastructure...
  
  

Switches running NX-OS

• Nexus 7000 series
• Nexus 5000 series
• Nexus 4000 (for IBM BladeCenter
  IBM BladeCenter
  The IBM BladeCenter is IBM's blade server architecture.-History:Originally introduced in 2002, based on engineering work started in 1999, the IBM BladeCenter was a relative late comer to the blade market. But, it differed from prior offerings in that it supported the full range of high powered x86...
  
  )
• Nexus 3000
• MDS 9500 FC Directors
• MDS 9222i FC Switch
• MDS 9100 FC Switches

Differences between IOS and NX-OS

• NX-OS does not support the login command to switch users.
• NX-OS does not distinguish between standard or extended access lists, all lists are named and "extended" in functionality.
• NX-OS did not support scp server prior to 5.1(1) release.
• In NX-OS, there is no "write" command to save the configuration like on IOS (one uses the "copy" command, instead). Instead, command aliases can be created to provide the "write" command.
• When accessing NX-OS, users go directly to EXEC mode
• SSH
  SSH
  - In science and technology :* Saffir–Simpson Hurricane Scale* Sea surface height, the topography of the ocean surface* Secure Shell, a network protocol for remote administration of Unix computers* Social sciences and humanities, a broad field of research...
  
   server is enabled while Telnet
  TELNET
  Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection...
  
  server is disabled by default in NX-OS

Releases

• NX-OS 5.2
• NX-OS 5.1
• NX-OS 5.0
• NX-OS 4.2
• NX-OS 4.1
• SAN-OS 3.3
• SAN-OS 3.2
• SAN-OS 3.1
• SAN-OS 3.0
• SAN-OS 2.1
• SAN-OS 2.0
• SAN-OS 1.0

External links

• intro
• data sheet