Router
A Router is a network device that enables you
the 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 de;vices.
The IOS has many features that enable the user to interact with the devices.
Router Components :
The Router requires certain hardware and
firmware components for proper functioning. These components enable the router
to enter the boot up process, load its operation system, and
configuration files.
A Routers has four different components.
·
ROM : – The Read Only Memory
(ROM ) is a non-volatile memory storage devices. ROM does not lose its
contents when the Power supply is turned off. The components of ROM decide the
boot process of the router.
1.
POST
2.
Bootstrap Program
3.
Mini – IOS
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 table, interface input, and output buffers.
Flash : - The flash memory in a
router is a non-volatile storage medium. The flash memory may contain IOS
images using which the router can boot. Flash memory is slow, as compared to
RAM. Therefore, if you compare the performance of both RAM and flash memory,
RAM provides a higher rate of performance.
NVRAM : - Non-Volatile Random
Access Memory ( NVRAM ) 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 batter. The start up file
and the configuration register for the router are present in the NVRAM. The
configuration register specifies the boot up options for the router.
Router installation
Every router has a specific manual according
to which you can assemble the router framework. The router ports may different
as per the series of the router.
To install or set up a Router:
1.
Mount the router framework as per the instructions in the Manuel.
2.
Connect the cables to the appropriate ports.
3.
Switch the power supply on.
Router
Boot up Process
The router requires all the above components
during its boot up. The router locates the IOS image during booting up. The IOS
images can be present in the RAM, Flash Memory, or an FTP server in the
network.
The router boot up process consists of five
steps : -
1.
Router performs the POST check for testing the hardware
components and memory.
2.
Bootstrap program is loaded and executed.
3.
Bootstrap program locates the IOS image from flash, RAM, or the
FTP server.
4.
Bootstrap program loads the IOS.
5.
IOS locates the configuration file present in the NVRAM.
6.
IOS loads the configuration file. The router after boot displays
the available interfaces, the network information and status of all the
interfaces.
7.
A message appears prompting to press the Enter key to continue.
You can press the enter key, To continue
working with the router.
Initial
Router Configuration
After the router boots, the router prompts for
initial configuration. The router can be configured using three different way :
-
·
Using the Security Device Manager – Automatically
starts for some routers.
·
Using the Set up command facility - Enables us to
configure a host name for the router, se passwords configure an interface for
communication with the management network.
·
Using the Command Line Interface - Enables manual
configuration of the router.
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