Cisco IOS, IOS-XR, and NX-OS comparison

Cisco IOS

  • Most common and legacy Operating System
  • Written using C programming language
  • Does not support symmetric multiprocessing
  • Use of shared memory space
  • Cisco IOS-XE is an extension of Cisco IOS

Cisco IOS-XR

  • Found on Cisco service provider routers
  • 64 bit architecture
  • Symmetric multiprocessing
  • Seperate memory spaces
  • Modular services
  • Built of Linux kernel
  • Somewhat similar to Cisco IOS

Cisco NX-OS

  • Found on Cisco Nexus switches located in data centers
  • Feature based licensing model
  • All Ethernet interfaces are called Ethernet. The FastEthernet, GigabitEthernet, TenGigabitEthernet interface naming conventions no longer exist
  • Default login administrator user is admin. It is no longer possible to login with just a password
  • Supports Checkpoint & Rollback feature (configuration and violation check)
  • EtherChannel(IOS) naming convention has been replaced by Port-Channel
  • Seperate memory spaces
  • Symmetric multiprocessing
  • Built of Linux kernel
  • Multiple High Availability features

Author: Chathura Ariyadasa

A highly talented IT professional with extensive experience and capabilities in performing a variety of IT Security, Computer Networking and IT Help Desk duties and responsibilities in the IT Department.