Introduction
A router is a network device that allows you to direct data
traffic to an appropriate destination. Routers maintain routing tables that
contain IP addresses of computers over the network. A router has different
components that enable its proper functioning. The Internetwork Operating
System (IOS) acts as an operating system for the network devices. The IOS has
many features that allow the user to interact with the devices. Router showing
in bellow picture
Router Components
A Cisco router does not contain disk storage mechanisms
such as hard disks. Therefore, the router requires certain hardware and
firmware components for proper functioning. These components allow the router
to enter the boot up process, load its operating system, and configuration
files. A router has six different components.
1. Processor
Cisco router has a processor (CPU) that executes the IOS
commands using the other router components. Cisco routers use two types of
processors such as Motorola 68030 and Orion/R4600. The Cisco IOS software makes
routing decisions and maintains routing tables using the processor. The
processor requires access to the memory either to get data for making routing
decisions or to get instructions for execution.
2. ROM
The Read Only Memory (ROM) is a non-volatile memory storage
device. ROM does not lose its contents when the power supply is turned off. The
components of the ROM decide the boot process of the router. To perform the ROM
upgrade, you must remove and replace pluggable chips on the
motherboard. The ROM consists of the following components:
1. POST
2.
Bootstrap Program
3.
Mini--IOS
4.
ROM Monitor
3. IOS ( Internetwork Operating System )
The operating system provides an interface
between the user and the hardware. Similarly, the IOS (Internetworking
Operating System) acts as an interface between the network devices and the
user. It is stored in the flash memory of the router. The Cisco IOS software
running on the router requires the processor of the system for configuring and
maintaining the network devices. The network devices perform many complex
calculations, based on user commands, during operation. These calculations
require an operating system that is user friendly and robust. The IOS is an
assembly of commands and functions that allow you to run the network device.
The IOS allows you to work with the devices and configure those using commands.
Cisco IOS 15.5(3)M is the latest OS version available.
4. RAM
The function of Random Access Memory (RAM) in
the router is similar to that of the memory in a computer. The RAM
is a volatile storage medium that loses data when the device is switched off.
The router RAM consists of the active IOS image that is loaded when the router
boots. The RAM temporarily stores the active configuration files, routing
tables and information in the input and output buffers of the router interface.
5. Flash
The flash memory in a router is a non-volatile
storage medium. It is basically EEPROM. The flash memory may contain IOS images
using which the router can boot. You can perform IOS software upgrades without
having to remove and replace chips
6. NVRAM
Non-Volatile RAM (NVR AM) is a type of random
access memory that stores configuration files for the router. The RAM is made
non-volatile by attaching it to a constant source of power supply such as a
battery. The startup file and the configuration register for the router are
present in the NVRAM. The configuration register specifies the bootup options
for the router.
7. Configuration Register
Configuration register is used to hold the
configuration of the router or configuration files of a router. The typical
value of configuration register is hexadecimal Ox2102. Using this value, the
router loads lnternetwork Operating System (IOS) from the flash memory and
configuration from the NVRAM.
Router Boot Sequence
Router Back panel
1. Power card Connections :- this
port is used for give power to the router
2. Power switch:- This switch is
used for ON/Off router
3. Auxiliary Port :- This Port
is used for connect modem to router
4. Console Port :- This port is
used for configure router. console cable is used for connecting router to computer
so we can configure router via computer
5. Fast Ethernet port:- This port is
used for connecting router to Local Area Network. normal LAN cable is used for
connecting router to LAN
6. Serial Port :- This port is
used for connecting router to another router and serial cable is used for
connecting router to router
In short router is a inter-networking device, inter-networking means communication between two or more different-different network. In an organization routers are using for connecting there branches to internet and they also can communicate with each other. Router means a device using for transferring packet to a destination root so it is called router.
In short router is a inter-networking device, inter-networking means communication between two or more different-different network. In an organization routers are using for connecting there branches to internet and they also can communicate with each other. Router means a device using for transferring packet to a destination root so it is called router.
Basic Cisco Router Configuration
No comments:
Post a Comment