Hi, Guys! Can you compare the various Cisco Operating Systems? I have read a post from the Reddit and find an interesting explanation about this topic. In this article, I will describe these operating systems and share the explanation.
(the cows are CPUs or independent processes on the same CPU.)
You have one cow. It chews grass.
Feature: IOS is a package of routing, switching, internetworking and telecommunications functions integrated into a multitasking operating system. Although the IOS code base includes a cooperative multitasking kernel, most IOS features have been ported to other kernels such as QNX and Linux for use in Cisco products or simulators such as Cisco VIRL.
Note: Not all Cisco products run IOS. Notable exceptions include ASA security products, which run a Linux-derived operating system, and carrier routers which run IOS-XR.
You have two cows. One chews grass and the other tells it what to chew.
Concept: IOS-XE is a train of Cisco Systems’ widely deployed Internetworking Operating System (IOS), introduced with the ASR 1000 series.
Feature: It is built on Linux and provides a distributed software architecture that moves many operating system responsibilities out of the IOS process and has a copy of IOS running as a separate process. Since it runs a copy of IOS, all CLI commands are the same between Cisco IOS and IOS-XE, in contrast to IOS-XR which has a completely different code base and its developers implemented quite a different CLI command set.
IOS vs. IOS-XE:
You have 27 cows. You have no idea what they do but when they fall over a new cow instantly reappears. Somehow they cost more than your house.
Concept: IOS XR is a train of Cisco Systems’ widely deployed Internetworking Operating System (IOS), used on their high-end Network Converging System(NCS), carrier-grade routers such as the CRS series, 12000 series, and ASR9000 series.
Features: IOS XR aims to provide the following advantages over the earlier IOS trains:
IOS vs. IOS-XR
Example BGP configuration for both IOS and IOS XR. More examples can be found in the Cisco document Converting Cisco IOS Configurations to Cisco IOS XR Configurations.
You have a penguin with a cow attached.
It yells instructions at a robot mega-cow. The robot chews grass really fast.
Concept: 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.
Switches running NX-OS:
IOS vs. NX-OS
You have a very old cow in a huge metal box that only speaks Spanish. Grass gives it diarrhea which it then spews out its 275 orifices at high speed.
Concept: CatOS (Catalyst Operating System) is the discontinued operating system for many of the Catalyst brand of legacy network switches. CatOS ran on switches such as 1200, 2948G, 4000, 4500, 5000, 5500, 6000, 6500 series. It was originally called XDI by the switching company Crescendo Communications, Inc. Cisco renamed it to CatOS when they acquired Crescendo in late 1993.
CatOS can still run on some of Cisco’s modular switches, “hybrid” mode. In hybrid mode, the NMP (switch processor) runs CatOS and the route processor runs Cisco IOS.
Does this information help you? Welcome to leave your comments!