CHAPTER 11

                In this chapter, it is mentioned network devices depends on two types of software for their operation. It is the operating system and the configuration. IOS is the operating system of network devices. It is like what we knew as operating system of a computer. Just like an operating system of a computer, it is also the system software for Cisco devices. It is accessible via CLI (Command Line Interface). And there are also different ways to access the CLI environment such as console, Telnet, and AUX port. And that’s all about operating system for network devices. Here’s the configuration. As what I have read, configuration is created by an administrator in order to provide the specific functionality of a specific Cisco device. A configuration file is of two types: 1) the running configuration file; and the 2) startup configuration file.

                Cisco IOS is also designed as a modal operating system, meaning, there are different modes of operation. And this chapter also showed the CLI hierarchical structure of the modes. Modes are identified in the command-line prompt which is unique to that mode. And several examples of commonly used modes are described in this chapter. Basic IOS command structures are also shown in this chapter as an example. Applying basic configurations using Cisco IOS are also discussed. And there are also testing done to verify its connectivity of the network.

KEY TERMS:

1.       IOS

-          Internetwork Operating System.

-          It provides basic routing and switching functions, it provides reliable and secure access to networked resources and it also provide network scalability. It also facilitates the basic operation of the device’s hardware components.

2.       Configuration files

-          Contains the Cisco IOS software commands used to customize the functionality of a Cisco device.

3.       Startup Configuration files

-          Is used during system startup to configure the device. The startup-config files are loaded into the RAM each time the router is reloaded or started. Once the configuration files is loaded into the RAM, it is then considered as the running config.

4.       Running Configuration Files

-          It is modified when the network administrator performs device configuration. Changes to the running config will immediately affect the operation of the Cisco device. Changes made in the running config must be saved before the device is powered down because unsaved changes will be lost if the device will be turned off since it is in RAM.

5.       Ping command

-          It is an effective way to test connectivity.

-          It provides a method for checking the protocol stack and IPv4 address configuration on a host.