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.
It is based on MontaVista Software embedded Linux and is inter-operable with other Cisco operating systems. The command-line interface of NX-OS is similar to that of Cisco IOS.
System Manager (sysmgr)
Persistant Storage Service (PSS)
Message & Transaction Services (MTS)
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
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
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.
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
4.1, 4.2, 5.0, 5.1, 5.2, 6.0, 6.1, 6.2, 7.0
