Chapter 11

Chapter 11 discuss all about configuring, installing, cabling and putting a media of router and other devices. It explains and discusses how to configure the router and switch using command line interface (CLI). These configuration procedures require the use of the CISCO Internetwork Operating System. There are several ways on how to access the CLI environment. The Console, Telnet or SSH, and AUX port. A console uses a low speed serial connection to directly connect a computer or terminal to the console port on the router or switch. Telnet require active networking services on the devices. There must be at least one active interface configured with a layer 3 address, such as an IPv4 address. Aux establish a CLI session remotely is via a telephone dial –up connection using a modem connected to the routers Aux port. Aux doesn’t require any networking service to configured or available on the device.
There are two types of configuration:
Running configuration
Start –up configuration
Running configuration - file that used during the current operation and stored in a RAM. Start- up configuration – file that used as back- up configuration and is loaded when the device is started, it stored in a Non-Volatile RAM. That is why, the file still remain even the CISCO device is turned off.

In CISCO IOS, there are different modes of operations. The User Executive mode which only allowed basic monitoring commands also referred as view- only mode and does not allowed the execution of any command to change the configuration of the device. The user exec mode is identified by the CLI prompts that ends with the > symbol like router> or switch>. The next is the privileged EXEC mode. The privileged exec mode can be identified by the prompt end with # symbol like router#. It shows the detailed examination of the router. Debugging and testing, file manipulation and remote access are usually done in this mode. In order to enter into the privileged mode from user exec mode, just type enable and enter. It will automatically enter into the privileged mode. Global configuration mode is a configuration mode that changes being made affect the operation of the device as a whole. It also used for accessing specific configuration modes. From privileged mode, just type configure terminal and enter then it will enter into the global configuration mode. It is identified by the prompts (config)#. There are also specific configuration modes like interface modes that configure the network interface, line mode that configure the lines and router mode that configure the parameters for one of the routing protocols. Upon configuring more than one device, it is better to put a name in every device so that it can easily identify to configure. To configure IOS hostname, just enter the hostname in the global configuration mode like router(config)# hostname HQ then enter. It will automatically change the device name. you can also put a password in configuring. You can used a console, vty and enable password in privileged mode. After configuring the device, in order to remain your configuration, just copy the running configuration into the start-up configuration so that whenever to turned on the device the configuration still there. You can test your device by pinging it into the other device. The ping command is used to verify the internal IP address configuration of the localhost. Just enter ping then the address and it will response according to the result