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Monday, November 29, 2010

EIGRP Configuration

In this module we will learn EIGRP configuration in cisco routers. EIGRP is hybrid form of IGRP protocol.
Below is the network architecture with all the configuration commands. Try to create similar type of network in Packet tracer and configure the routers.

Note: EIGRP supports VLSM  i.e. it is a classless protocol. IGRP is a classfull protocol i.e. it does not understand Subnets. We will discuss in detail about VLSM concept in future sessions.




CONFIGURATION:

R1:
After assigning desired IP addresses to the serial and fast Ethernet interfaces, clock rate will be set following by no shutdown command.
Router command is used to configure the router and  Network command is used to mention the network where EIGRP protocols will flow.
Note: Here 444 is the autonomous systems numbers. It should to be same in both the routers for the communication to happen.

R2:
R2 configuration is similar to R1.

VERIFICATION:

Show commands:
Router#sh ip Eigrp topology
Router#sh ip Eigrp neighbor

*you can use other commands, mentioned in previous posts, to verify configuration.

Sunday, November 28, 2010

IGRP Configuration

Welcome again! As I mentioned in earlier post, RIP considers only the distance and direction for routing. So we came up with IGRP protocol which considers bandwidth, distance , load , delay and other factors.
In this module, we will learn about IGRP configuration in cisco routers.
As shown below, I have used similar type of network as used for RIP configuration. All configuration commands, for every router, has been explained in the diagram. Try to create similar network using Packet tracer tool and configure the routers.

CONFIGURATION:

R1:
First we have assigned ip address to the interfaces, followed by the clock rate and no shut down command.
Then we configured IGRP protocol using "Router IGRP 222" command. Then mention the Network ID where you want the protocol to flow.
Note: Here 222 is the Autonomous System number. It may range from 1 to 65535. As a very large network is difficult to manage, the network is divided into autonomous systems and are numbered. It is done to manage the network and for administration convenience. Routers with the same autonomous systems only will communicate.

R2:
R2 configuration is similar to R1. Mention the same autonomous number as used in R1.

VERIFICATION:

To check dynamic routing protocols:
Router#sh ip protocols

Show commands:
Router#sh ip IGRP

*you can use other commands, mentioned in previous posts, to verify configuration.


Thank you for reading this post. Looking forward to seeing you in next post :-)

RIP Configuration

In this module we will learn how to configure RIP (version 2) in cisco routers.
I have used a very simple network architecture to demonstrate the configuration, as shown below.
Try to create similar network using Packet Tracer tool and configure the router using the commands as shown in the picture.

CONFIGURATION

R1:
First we assigned ip addresses to the serial and fast Ethernet interfaces and then set clock rate for serial link followed by no shutdown command.
After assigning ip addresses to the interfaces, "Router RIP" command is used to configure RIP. Then you select the version number (RIP Protocol has two version i.e. Version 1 and Version 2).
Then you select the network where you want the RIP Protocols to flow.

R2:
R2 configuration is similar to R1 configuration

VERIFICATION:

To check dynamic routing protocols:
Router# sh ip protocols

Show commands:
Router# sh ip RIP

*you can use other commands, explained in previous posts, to verify configuration.

Note: RIP considers only the distance and direction for routing. Since it was not efficient, IGRP came up as it considered bandwidth , distance , load , delay and other factors.
We will discuss IGRP configuration in the next module.

Hope you enjoyed reading this post. Thank you !

Wednesday, November 24, 2010

Static Routing (Leased Line)

Welcome Everyone !
In this session we will learn Static Routing configuration in Cisco routers.
I have designed a simple network, using Packet tracer 5.0, to configure and discuss this concept.
In this network, I have used 2 Routers (R1 & R2), 2 Switches (S1 & S2) and 2 workstations (PC1 and PC2).
To configure static routing in this network, all commands used are shown in the network diagram.

CONFIGURATION

R1:
In router R1 first we will set IP address to the Serial port and fast Ethernet port. After assigning IP address we will run "no shutdown" command to bring the node live. In Serial port , we will also set the clock speed. I have used 64000 in this scenario.

R2:
R2 configuration is similar to R1 configuration.



VERIFICATION
You can verify the configuration by using the below commands:

Show commands to check IP addresses:
Router#sh run
Router#sh interfaces
Router#sh interface s2/0
Router#sh interface f0/0
Router#sh ip interface brief

To check Routing table:
Router#sh ip route

CISCO IOS Commands

This is a list of some important Cisco IOS commands and its description. IOS is the software used on most of Cisco Routers & network switches.
These IOS commands has been categorized on the basis of the previlage mode available in the device.
Usually we have four modes, these are:

User Mode
Enable Mode
Global Configuration Mode
Specific Configuration Mode



Note: Please visit www.cisco.com for more IOS Commands.

We will learn in detail about these commands and their applications in future sessions.

Securing Router

In this CCNA lab series we will learn how to secure our Router Console port and the Terminal sessions. I am going to set up my lab using Packet tracer 5.0, which is one of the best Router simulator available for practice and experiments. Before going through this hands on session, please check my article on Cisco IOS commands, this will give you brief idea about all the commands available in different different modes. Also, you can refer my article on Subnetting, this will help you to understand the IP addressing of the network devices.

Okay ! lets first set up our virtual lab.I am using a simple network architecture where I have taken 2 routers (R1 and R2) , 1 Switch SW1 and 3 Workstations (PC-1 and PC-2 and Router Console. In this scenario we will secure our Router R1.
All configuration commands have been mentioned in the network diagram.



CONFIGURATION

In R1:
1) we have assigned ip address to the serial port and the fast Ethernet port. In serial port, we also declared the clock rate speed , which is mandatory for all serial clock links.
2)After that, we have set console password as "cisco".
3) Then we have set password for Telnet sessions.
here the user mode password is "habib" and the enable encrypted password is "enaa".
Note: Routers support 5 telnet sessions and same password used for all.

In R2:
1)In R2, we have assigned ip address to the serial link and set the clock speed as 64000.

VERIFICATION
Console security:
To check, try to login to terminal session of router R1 via Router Console (which is directly connected to R1). Here the password to login is "cisco".

Terminal Security:
Try to launch a telnet session from PC-1 (commands are shown in the diagram)
first it will ask password for user mode(password is habib)
and then it will ask password for enable mode (password is enaa)


Hope you enjoyed reading this post. Let me know if have any suggestions or comments. I will be more than happy to include more advanced topics in future posts. Thank you !

Thursday, November 11, 2010

IP Address Classes & Subnetting

IP Address Classes


Importent Note:

  • Class A addresses 127.0.0.0 to 127.255.255.255 cannot be used and is reserved for loopback and diagnostic functions.
  • a.b.c.1  to  a.b.c.10 – usually routers and servers
  • a.b.c.11  to  a.b.c.204 – usually workstations
  • a.b.c.241  to  a.b.c.254 – usually UNIX (or Linux) hosts
  • 10.0.0.0  to 10.255.255.255 – usually Internal networks
  • 172.16.0.0  to  172.31.255.255 – usually Intranets not connected to the Internet
  • 192.168.0.0  to 192.168.255.255 – usually networks connected to the Internet
    (and usually behind a firewall)
IP Subnet Table



Wednesday, November 10, 2010

Introduction to Servers

Servers
A server is a hardware device which performs services for the clients connected to it. The service delivered depends on what the server is being used for. For example, an email server routes and stores email for its clients. A server with a large storage capacity might be used to store large files for its clients.
3 server form factors:
  • Tower
  • Rack
  • Blade (newer form factor packs more processing power in a smaller space)
The choice depends largely on the number of clients being served. A small tower server might handle 1-10 clients with ease. A large office complex with 1000's of connected PC's would require either a rack or blade setup.


Tower
In theory any computer can be used as a server. You could take an old PC in your house and use it to serve up media files maybe store your mp3's?
A tower case is significantly larger than a standard ATX case. Tower servers are typically used for small business with perhaps <1,000 users.
Example of a tower server




Rack
A server rack looks like a tall cabinet with slots for components to slide in. A standard sized component for a rack is 1U (19 inches wide X 1.75 inches tall) and a rack cabinet is 42U. A rack is a much more practical solution for squeezing a large amount of hardware into a small space. A server rack can be expanded to handle 1,000's of users.
Example of a rack Server




Blade
Blade technology is essentially an improvement on the traditional server rack. The "blades" contain the bare minimum of components. The blade case supplies all the power and network connectivity and cooling. This means you can get up to 100 processing blades in the same space as a 42U rack.The blades work together and are controlled by the operating system.
Example of a blade server




Each particular type of server is generally defined by its configuration and software which enables it to communicate with intermediate client machines.
According to the services it provides, Servers can be classified into many types, few are listed below:

1.Application servers
2.Audio/Video servers
3.Chat servers
4.Fax servers
5.FTP servers
6.Groupware servers
7.IRC(Internet Relay Chat) servers
8.List Servers
9.Mail servers
10.News servers
11.Proxy servers
12.Telnet servers
13.web servers
14.Database servers
15.Staging servers
16.Backup servers
17.Directory server(Enterprise access servers)
18.DNS/DHCP servers
19.Management server
.
.
Phew! ;-)


Server-Client Network Model
If you are interested to know how Client machines are connected to Servers, then you should have a look to the below Network diagram. You will find lot networking concepts applied to this model. We will cover these advanced Networking concepts in our future sessions as well.


- This was just an introduction session. After completing few basic concepts, in coming sessions, we  will focus on Server Configuration, Management and Administration part. Thank you !

Tuesday, November 9, 2010

How to Learn

Hello everyone ! welcome to our first session where I will share few methods to be a smart learner. All of us know how to learn but here I tried to consolidate few important tips which we should follow while learning Technical stuffs.

1) Slow Down                  
Don’t just read. Stop and think. When the book asks you a question, don’t just skip to the answer. Imagine that someone really is asking the question. The more deeply you force your brain to think, the better chance you have of learning and remembering.
                                                                                                                             

2) Do the Exercises and Take Your Own Notes

Don’t just look at the exercises. Go through it and try to answer the questions. If you are unable to answer any question then it’s fair to check the solution and understand the concept.

                                         


3) Don’t  Try to Learn Multiple Things
After Reading or listening something, actual data transfer starts when you stop learning it. Brain need some time on its own, to do more processing. If are putting something during processing time, some of what you just learned will be lost.
                                                                                                                

4) Drink Water
Your brain works best in a nice bath of fluid. Dehydration (which can happen before you ever feel thirsty) decreases cognitive function.
                                   

5) Use Pencil 
Use a pencil and note important points. If you have done any mistake then you can erase or modify it any time J. There’s plenty of evidence that physical activity while learning can increase the learning.
                                                                                                     

6) Listen to Your Brain
Pay attention to whether your brain is getting overloaded. If you find yourself starting to skim the surface or forget what you just read, it’s time for a break.
                                

7) Feel Something
Your brain needs to know that this matters. Get involved with the stories. Make up your own captions for the photos. Groaning over a bad joke is still better than feeling nothing at all.
                                                                                                                 


And the most important thing: Always remember your Aim



-I hope you enjoyed this post and now we are ready to start this long technical Journey together