This write-up will cover a few points that you will likely be tested for the CCNA regarding the configuration of standard Cisco IOS router operation.

This write-up will cover a few points that you are going to be tested for the CCNA regarding the configuration of fundamental Cisco IOS router operation. IOS (Internetwork Operating Program) will be the software program operating system running on most Cisco network devices, including switches and routers. To configure any Cisco network device you will need to master the Cisco IOS Download Configuration Commands and use the Command Line Interface (CLI) to configure and troubleshoot a Cisco device.

Tips on how to connect to a Router so as to Configure it:

You could connect to a Download Cisco IOS Router either directly or remotely. For the first time when the device is not configured but, you ordinarily connect directly having a console cable via the CON port or remotely by dialing into a modem connected towards the AUX port. These are called "out-of-band" connection techniques. Right after you configure the router and assign IP addresses to its interfaces, you may connect towards the router from the network with an "in-band" connection approach working with Telnet or SSH.

Router Configuration Modes

Right after connecting to a Cisco Router (let's say working with a console), you will be presented with the Command Line Interface in which you type and enter configuration commands. Right after typing a command, you press enter plus the command is automatically active on the device. For example working with the "shutdown" command on an interface, automatically disables the interface. Now, you can find two Router Configuration Modes (or access modes):

User EXEC Mode: Permits the administrator to access only limited monitoring commands. You could not in fact make any configurations from this mode. The command prompt on this mode is "router>"
Privileged EXEC Mode: Permits the administrator to access all device commands, such as those employed for configuration and management, and could be password protected to enable only authorized users to access the device at this "full-access" level. This mode is also called enable mode for the reason that you get to it with the enable command. The command prompt on this mode is "router#". From the privileged EXEC mode you may begin configuring the device by typing "configure terminal".

Router Memory Sorts

A Cisco router has four memory types:

ROM: This really is exactly where the POST script of the router is located. The POST software program (Power On Self Test) is employed through startup to carry out the initial hardware checking of the device. The ROM also holds a mini-IOS employed for password recovery.
RAM: This really is exactly where the running configuration is located. Right after the device boots up, the IOS software program is loaded into RAM. Also, RAM holds routing tables, network parameters through operation and so on. When configuring the router, we in fact change the running-configuration which as we stated is stored into RAM
NVRAM: When we save the running-configuration (working with the command "write") it really is stored into the NVRAM and becomes the startup-configuration. Right after rebooting the router, the startup-configuration is loaded from the NVRAM.
Flash: This really is like the hard-disk of a PC. It holds the IOS software program image file and any backup configurations that you might save from time to time.

When you problem the "show running-configuration" command on the router you instruct the device to display the present running configuration in RAM. When you problem the "show startup-configuration" command you instruct the router to display the stored configuration within the NVRAM.

Harris Andrea is actually a Cisco Certified Skilled (CCNA, CCNP, CCSP) with far more than 10 years of expertise within the networking field. He is presently employed as a senior network engineer in a leading ISP organization.