Cisco NX-OS explained

Cisco NX-OS
Developer:	Cisco Systems
Source Model:	Closed source
Family:	Unix-like
Working State:	Current
Website:	Cisco NX-OS
Latest Release Version:	10.4

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 switches.^[1]

It is based on Wind River Linux and is inter-operable with other Cisco operating systems. The command-line interface of NX-OS is similar to that of Cisco IOS.^[2]

Recent NX-OS has both Cisco-style CLI and Bash shell available. On NX-OS 7.0(3)I3, the output from uname with the -a command line argument might look like the text below:$ uname -aLinux version 3.4.91-WR5.0.1.13_standard+ (divvenka@sjc-ads-7035) (gcc version 4.6.3 (Wind River Linux Sourcery CodeBench 4.6-60)) #1 SMP Tue Feb 6 12:43:13 PST 2018

Core features

System Manager (mis|sysmgr)
Persistent Storage Service (PSS)
Message & Transaction Services (MTS)

Additional features

Fibre Channel and FICON
FCIP
FCoE (Nexus 5000/7000 linecards)
iSCSI
IPsec
Scheduling
NPIV NX Port ID Virtualization
Inter–VSAN Routing
VSAN
Zoning (Hard zoning)
Callhome
Cisco Fabric Services (distributed configuration)
SSH and Telnet
Storage Media Encryption
Port Channels
Cisco Data Mobility Manager
Fibre Channel Write Acceleration

Switches running NX-OS

Nexus B22 (HP, Dell, Fujitsu)
Nexus 9000 series
Nexus 7700 series
Nexus 7000 series
Nexus 6000 series
Nexus 5000 series
Nexus 4000 (for IBM BladeCenter)
Nexus 2000 series
Nexus 3000
Nexus 1000V
MDS 9700 FC Directors
MDS 9500 FC Directors^[3]
MDS 9250i FC Switch
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.^[4]
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 authenticate directly to their assigned privilege level.
SSH server is enabled while Telnet server is disabled by default in NX-OS.^[5]

Releases

4.1, 4.2, 5.0, 5.1, 5.2, 6.0, 6.1, 6.2, 7.0, 9.2, 9.3, 10.1

References

Web site: Cisco NX-OS Software: Business-Critical Cross-Platform Data Center OS. August 10, 2014. Cisco. June 3, 2017.
Web site: Nexus: Hands on with NX-OS, Part#1. Mark. Lewis. April 12, 2008. NetworkWorld.com. June 3, 2017.
Cisco Product Brocuhure Cisco MDS 9500 Series of Multilayer Directors, visited 18 May 2012
Web site: Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.1.
Web site: Cisco NX-OS/IOS Configuration Fundamentals Comparison. June 3, 2017.