Introduction to Cisco NX-OS: NX-OS vs IOS

• Cisco Nexus OS Interfaces – NX-OS interfaces are all listed as Ethernet interfaces (for data interfaces). In contrast, IOS uses a description based on speed, such as Gigabit or 10 Gigabit.

• When you log in to IOS, you are prompted for an enable password to move from user EXEC mode into enabling (also called privileged) EXEC mode. NX-OS associates a privilege level for every to EXEC mode.

• NX-OS has a management Virtual Routing and Forwarding (VRF) instance per Nexus switch as well as a default VRF that all other interfaces belong to. To get access to remotely manage a Nexus switch, you must configure the Management interface.

• NX-OS uses two binary images per-version of the operating system to be downloaded and installed (kickstart and system), except for Nexus 9000. Cisco IOS is a single binary image that is downloaded and installed by the network administrator.

• To enable features in NX-OS, the feature command is used per features, such as feature OSPF and feature EIGRP to enable these Layer 3 routing protocols. In Cisco IOS, the command IP routing enables all the processes for every routing protocol a given operating system image will support.