Lab.4 Router configuration II

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28 Οκτ 2013 (πριν από 3 χρόνια και 9 μήνες)

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Lab.
4



Router configuration II



Learning Objectives:



To learn how to configure different dynamic routing protocols.



To learn how to configure static routing.



To learn how to perform Cisco router management.



To learn how to view and check the routing
table.

Routing Information Protocol RIP

Routing is the process that a router uses to forward packets toward the destination network. A
router makes decisions based upon the destination IP address of a packet. All devices along the
way use the destination I
P address to send the packet in the right direction to reach its destination.
To make the correct decisions, routers must learn how to reach remote networks. When routers
use dynamic routing, this information is learned from other routers. When static rout
ing is used, a
network administrator configures information about remote networks manually.

Since static routes are configured manually, network administrators must add and delete static
routes to reflect any network topology changes. In a large network,
the manual maintenance of
routing tables could require a lot of administrative ti
me.
Static routing is not as scalable as
dynamic routing because of the extra administrative requi
rements.
A routing protocol allows
routers to share information about network
s and their proximity to each other. Routers use this
information to build and maintain routing tables.

Examples of r
outing protocols are
Rou
ting Information Protocol (RIP)
,
Interior
Gateway Routing
Protocol (IGRP)
,
Enhanced Interior Gateway Routing Proto
col (EIGRP
) and

Open Shortest Path
First (OSPF)

Routing Information Protocol (RIP) is one protocol in a series of routing protocols based on
Bellman
-
Ford (or distance vector) algorithm.
Distance vector protocols do not have an entire map
of the network and

only learns about the network through it’s neighbor routers.
Interior Gateway
Protocol (IGP) lets routers in the same autonomous system exchange routing information in the
way of periodic RIP updates. Routers transmit their own RIP updates to neighboring
networks
and listen to the RIP updates from the routers on those neighboring networks to ensure their
routing table reflects current state of the network and all the best paths are available. Best path is
a path with the fewest hops (router gateways).
The
major task in the routing configuration mode
is to indicate IP network numbers. Dynamic routing uses broadcasts and multicasts to
communicate with other routers.

An example of a routing configuration is as follows:



BHM(config)#router rip



Selects RIP as
the routing protocol



BHM(config
-
router)#network 10.0.0.0



Specifies a directly connected network
number.



BHM(config
-
router)#network 192.168.13.0



Specifies a
nother

directly
connected network
number if exists.

Enhanced
Interior Gateway Routing Protocol (
E
IGRP)

E
IGRP is a distance vector routing protocol developed by Cisco.
E
I
GRP
advertise all the
networks for a particular AS. By default, the
E
IGRP routing protocol uses bandwidth and delay
as metrics. Additionally,
E
IGRP can be configured to use a combinat
ion of variables to determine
a composite metric. These variables are as follows:



Bandwidth

,
Delay

,
Load
,
Reliability

To configure the
E
IGRP routing process, use the
router
e
igrp

configuration command. To shut
down an
E
IGRP routing process, use the
no

form of this command.
The command syntax is as
follows:

RouterA(config)#router
e
igrp as
-
number

RouterA(config)#no router
e
igrp as
-
number

To specify a list of networks for
E
IGRP routing processes, use the
network

router configuration
command. To remove

an entry, use the
no

form of the command

Configuring static routes

Step 1 Determine all desired prefixes, masks, and addresses. The address can be either a local
interface or a next hop address that leads to the desired destination.

Step 2 Enter global c
onfiguration
modes
.

Step 3 Type the
ip route

command with a prefix and mask followed by the corresponding address
from Step 1. The administrative distance is optional.

Step 4 Repeat Step 3 for all the destination networks that were defined in Step 1.

Tes
ting Network by show commands

The
show ip route

command can be used to verify that routes received by
Routing protocols
which are either static or dynamic

are installed in the routing table. Examine the output of the
command and look for RIP routes signified by "R". Remember that the network will take some
time to converge so the routes may not appear immediately.

Cisco Discovery Protocol (CDP)

Sometimes network documentation is incomplete or inaccurate. Cisco Discovery Protocol (CDP)
is a useful tool in these situations because it can build a basic picture of a network. CDP is a
media and protocol independent, Cisco proprietary protocol used for

neighbor discovery.
CDP
operates at the data link layer and allows two systems to learn about each other, even if they use
different network layer protocols.
CDP will only show information about directly connected
neighbors but it is

still a powerful tool.

Telnet is a TCP/IP
-
based application that allows remote
connection to the router command
-
line interface (CLI) for configuration, monitoring, and
troubleshooting purposes. Telnet is an essential tool for network professionals.

Each device that is configur
ed for CDP sends periodic messages, which are known as
advertisements, to directly connected Cisco devices. The advertisements also contain time
-
to
-
live
or hold

time information, which indicates the length of time that receiving devices should hold
CDP inf
ormation before they discard it. Each device also listens to periodic CDP messages that
are sent by others to learn about neighbor devices.

Use the
show cdp neighbors

command to display CDP updates on the local device.

Command

Purpose

cdp enable

Enables

CDP on an interface

show cdp
neighbors [type
number] [detail]

Displays the type of device that has been discovered, the name of the
device, the number and type of the local interface or port, the number
of seconds the CDP advertisement is valid for the p
ort, the device type,
the device product number, and the port ID


Managing configuration files using TFTP

In a Cisco router or switch, the active configuration is in RAM and the default location for the
startup configuration is NVRAM. The startup configuration should be backed up in case the
configuration is lost. One of these backup copies of the configuratio
n can
be stored on a TFTP
server.

-

Enter the command
copy running
-
config tftp
.

-

Enter the IP address of the TFTP server to store the configuration file.

-

Enter the name to assign to the configuration file or accept the default name.

-

Type yes to con
firm each choice.

Vice versa, t
he backup configuration file can be loaded from a TFTP server to restore the router
configuration. The steps below outline this process:

-
Enter the command
copy tftp running
-
config
.


Managing configuration files using copy
and paste

Another way to create a backup copy of the configuration is to capture the output of the
show
running
-
config

command, c
opy
and
paste
the output
into a text fi
le
.

This file will need to be
edited before it can be used to restore the router configuration.


Procedure


Use

the
commands explained by the instructor to accomplish the
following procedure
. As
you finish each part of the procedure, fill in yo
ur in lab repor
t related requirements
.

You
are

advised also to practice these commands at home using the
packet trace
r simulator.


Part 1 Basic router and laptop setup


Based on the graph below and the assigned router

by your instructor
,

configure your
router to achieve the following
:



1
.

Connect
your
PC to

your router using the proper UTP cable
.

2
.

Connect the router console port to the serial port of the laptop.

3
.

Capture your entire configuration before you start
.

4
.

Configure the router with the following




Name the router with your name
.




Configure the router line console

and VTY

p
assword
s

to be PSUT
.




Configure the router to have an enable secret (Student)
.



Configure router
and pc interfaces

with the proper IP
’s

as
shown in the

graph

below.




Test connectivity to the pc by

both PING and telnet instr
uctions.



Ping the Pc from Router and Ping the router from PC.



Try to configure the router from the pc

using telnet.




Part 2 Start testing routing protocols


1
.

Build the
topology above and use the commands you learned to configure RIP on your
router,
make sure to configure carefully the
DCE and DTE sides.


2
.

Use the show IP

route command to check the routing table.


3
.

Test connectivity to other routers and stations using the
ping and telnet commands.


4
.

Use show running configuration, show interfaces, show controllers and comments on
its functions.


5
.

Change the routing protocol to be EIGRP 20 and configure the router again for it,
w
hat is the output of the show IP

route now?


6
.

Ch
ange the routing protocol to be OSPF area 0 and configure the router again for it,
w
hat is the output of the show IP

route now?


7
.

Change the routing protocol to static and configure the router again for it, w
hat is
the output of the show IP

route now?


Part 3

Managing the Cisco router


8
.

Use the show CDP

neighbor command to know

the mod
el of each directly connected
router and record it
.
B
e careful, you can only use CDP

w
ith neighbor routers, to use
CDP

to discover a far router telnet its neighbor then use

show CDP

neighbors.


9
.

Establish connectivity with the laptop as a tftp server and copy your running
configuration to
it,

try also to save the IOS on the tftp server.


10
.

Follow the instructor demo to learn how to recover lost
router

password, wr
ite the
procedure in your report
.