This shape-changing bot is built of many simple modules which it can move around, allowing it to adapt to different tasks and build 3-dimensional structures. Click to enlarge.
A computer network is a system in which computers are connected to share information and resources. The connection can be done as peer-to-peer or client/server. This web site reviews the techniques you can use to set up and possibly manage a network for home or a small business.
Computer Networking
Computer networking is the engineering discipline concerned with the communication between computer systems or devices. A computer network is any set of computers or devices connected to each other with the ability to exchange data.Computer networking is sometimes considered a sub-discipline of telecommunications, computer science, information technology and/or computer engineering since it relies heavily upon the theoretical and practical application of these scientific and engineering disciplines.
The three types of networks are: the Internet, the intranet, and the extranet. Examples of different network methods are:
Local area network (LAN), which is usually a small network constrained to a small geographic area. An example of a LAN would be a computer network within a building.
Metropolitan area network (MAN), which is used for medium size area. examples for a city or a state.
Wide area network (WAN) that is usually a larger network that covers a large geographic area.
Wireless LANs and WANs (WLAN & WWAN) are the wireless equivalent of the LAN and WAN.
History of cisco
A lot of readers may already be familiar with Cisco and what they do. However,
those of you who are new to the field, just coming in fresh from your
MCSE, and those of you who maybe have 10 or more years in the field but
wish to brush up on the new technology may appreciate a little background
on Cisco.
In the early 1980s, Len and Sandy Bosack, a married couple who worked
in different computer departments at Stanford University, were having
trouble getting their individual systems to communicate (like many married
people). So in their living room they created a gateway server that made it
easier for their disparate computers in two different departments to communicate
using the IP protocol. In 1984, they founded cisco Systems (notice the
small
c
) with a small commercial gateway server product that changed networking
forever. Some people think the name was intended to be San Francisco
Systems but the paper got ripped on the way to the incorporation
xxiv
Introduction
lawyers—who knows? In 1992, the company name was changed to Cisco
Systems, Inc.
The first product the company marketed was called the Advanced Gateway
Server (AGS). Then came the Mid-Range Gateway Server (MGS), the
Compact Gateway Server (CGS), the Integrated Gateway Server (IGS), and
the AGS+. Cisco calls these “the old alphabet soup products.”
In 1993, Cisco came out with the amazing 4000 router and then created
the even more amazing 7000, 2000, and 3000 series routers. These are still
around and evolving (almost daily, it seems).
Cisco has since become an unrivaled worldwide leader in networking for
the Internet. Its networking solutions can easily connect users who work
from diverse devices on disparate networks. Cisco products make it simple
for people to access and transfer information without regard to differences
in time, place, or platform.
In the big picture, Cisco provides end-to-end networking solutions that
customers can use to build an efficient, unified information infrastructure
of their own or to connect to someone else’s. This is an important piece in
the Internet/networking–industry puzzle because a common architecture
that delivers consistent network services to all users is now a functional
imperative. Because Cisco Systems offers such a broad range of networking
and Internet services and capabilities, users needing regular access to their
local network or the Internet can do so unhindered, making Cisco’s wares
indispensable.
Cisco answers this need with a wide range of hardware products that
form information networks using the Cisco Internetwork Operating System
(IOS) software. This software provides network services, paving the way for
networked technical support and professional services to maintain and optimize
all network operations.
Along with the Cisco IOS, one of the services Cisco created to help support
the vast amount of hardware it has engineered is the Cisco Certified
Internetwork Expert (CCIE) program, which was designed specifically to
equip people to effectively manage the vast quantity of installed Cisco networks.
The business plan is simple: If you want to sell more Cisco equipment
and have more Cisco networks installed, ensure that the networks you install
run properly.
However, having a fabulous product line isn’t all it takes to guarantee the
huge success that Cisco enjoys—lots of companies with great products are
now defunct. If you have complicated products designed to solve complicated
problems, you need knowledgeable people who are fully capable of
Introduction
xxv
installing, managing, and troubleshooting them. That part isn’t easy, so
Cisco began the CCIE program to equip people to support these complicated
networks. This program, known colloquially as the Doctorate of Networking,
has also been very successful, primarily due to its extreme difficulty.
Cisco continuously monitors the program, changing it as it sees fit, to make
sure that it remains pertinent and accurately reflects the demands of today’s
internetworking business environments.
Cisco’s Network Support Certifications Cisco has created new certifications that will help you get the coveted CCIE, as well as aid prospective employers in measuring skill levels. Before these new certifications, you took only one test and were then faced with the lab, which made it difficult to succeed. With these new certifications, which add a better approach to preparing for that almighty lab, Cisco has opened doors that few were allowed through before.
Cisco Certified Network Associate (CCNA) 2 The CCNA certification is the first in the new line of Cisco certifications, and it is a precursor to all current Cisco certifications. With the new certification programs, Cisco has created a type of stepping-stone approach to CCIE certification. Now, you can become a Cisco Certified Network Associate for the meager cost of this book , plus $100 for the test. And you don’t have to stop there—you can choose to continue with your studies and achieve a higher certification, called the Cisco Certified Network Professional (CCNP). Someone with a CCNP has all the skills and knowledge he or she needs to attempt the CCIE lab. However, because no textbook can take the place of practical experience, we’ll discuss what else you need to be ready for the CCIE lab shortly. xxvi Introduction Why Become a CCNA? Cisco, not unlike Microsoft or Novell, has created the certification process to give administrators a set of skills and to equip prospective employers with a way to measure skills or match certain criteria. Becoming a CCNA can be the initial step of a successful journey toward a new, highly rewarding, and sustainable career. The CCNA program was created to provide a solid introduction not only to the Cisco Internetwork Operating System (IOS) and Cisco hardware, but also to internetworking in general, making it helpful to you in areas that are not exclusively Cisco’s. At this point in the certification process, it’s not unrealistic to imagine that future network managers—even those without Cisco equipment—could easily require Cisco certifications for their job applicants. If you make it through the CCNA and are still interested in Cisco and internetworking, you’re headed down a path to certain success. What Skills Do You Need to Become a CCNA? To meet the CCNA certification skill level, you must be able to understand or do the following: Install, configure, and operate simple-routed LAN, routed WAN, and switched LAN and LANE networks. Understand and be able to configure IP, IGRP, IPX, serial, AppleTalk, Frame Relay, IP RIP, VLANs, IPX RIP, Ethernet, and access lists. Install and/or configure a network. Optimize WAN through Internet-access solutions that reduce bandwidth and WAN costs, using features such as filtering with access lists, bandwidth on demand (BOD), and dial-on-demand routing (DDR). Provide remote access by integrating dial-up connectivity with traditional, remote LAN-to-LAN access, as well as supporting the higher levels of performance required for new applications such as Internet commerce, multimedia, etc.
How Do You Become a CCNA?
The first step to becoming a CCNA is to pass one little test and—poof!—
you’re a CCNA. (Don’t you wish it were that easy?) True, it’s just one test,
Introduction
xxvii
but you still have to possess enough knowledge to understand (and read
between the lines—trust me) what the test writers are saying.
I can’t stress this enough—it’s critical that you have some hands-on experience
with Cisco routers. If you can get ahold of some 2500 routers, you’re
set. But if you can’t, we’ve worked hard to provide hundreds of configuration
examples throughout this book to help network administrators (or people
who want to become network administrators) learn what they need to
know to pass the CCNA exam.
One way to get the hands-on router experience you’ll need in the real
world is to attend one of the seminars offered by Globalnet Training Solutions,
Inc., which is owned and run by me. The seminars are six days long
and will teach you everything you need to become a CCNA and even a
CCNP. Each student gets hands-on experience by configuring at least two
routers and a switch. See
www.lammle.com
for more information.
In addition, Cyberstate University provides hands-on Cisco router
courses over the Internet using the Sybex Cisco Certification series books.
Go to
www.cyberstateu.com
for more information. And Keystone Learning
Systems (
www.klscorp.com
) offers the popular Cisco video certification
series featuring me.
If you are new to networking, you should take a look at
CCNA JumpStart
by Patrick Ciccarelli and Christina Faulkner (Sybex, 1999). This book will
give you the background necessary before jumping into more advanced networking
with Cisco routers.
Check out this book’s CD for a demo of the Sybex
CCNA Virtual Lab etrainer
, which can give you hands-on experience working with both routers
and switches. You can also check out
www.routersim.com
for another
router simulator.
In addition to this book, there are other useful ways to supplement your studies
for the CCNA exam. CiscoTests (
http://www.networkstudyguides.com
)
offers an online study guide with sample questions and information about the
most current release of the CCNA, CCNP, and CCIE exams.
For the best practice Cisco exam questions on the market, try
www.boson.com
.
xxviii
Introduction
Cisco Certified Network Professional (CCNP)
Cisco Certified Network Professional (CCNP), Cisco’s new certification, has
opened up many opportunities for those individuals wishing to become
Cisco-certified but lacking the training, the expertise, or the bucks to pass the
notorious and often failed two-day Cisco torture lab. The new Cisco certifications
will truly provide exciting new opportunities for the CNE and MCSE
who are unsure of how to advance to a higher level.
So, you’re thinking, “Great, what do I do after passing the CCNA exam?”
Well, if you want to become a CCIE in Routing and Switching (the most popular
certification), understand that there’s more than one path to that muchcoveted
CCIE certification. The first way is to continue studying and become
a Cisco Certified Network Professional (CCNP), which means four more
tests, in addition to the CCNA certification.
The CCNP program will prepare you to understand and comprehensively
tackle the internetworking issues of today and beyond—and it is not limited
to the Cisco world. You will undergo an immense metamorphosis, vastly
increasing your knowledge and skills through the process of obtaining these
certifications.
While you don’t need to be a CCNP or even a CCNA to take the CCIE
lab, it’s extremely helpful if you already have these certifications.
What Skills Do You Need to Become a CCNP?
Cisco demands a certain level of proficiency for its CCNP certification. In
addition to mastering the skills required for the CCNA, you should have the
following skills for the CCNP:
Installing, configuring, operating, and troubleshooting complex
routed LAN, routed WAN, and switched LAN networks, along with
dial-access services
Understanding complex networks, such as IP, IGRP, IPX, async routing,
AppleTalk, extended access lists, IP RIP, route redistribution, IPX
RIP, route summarization, OSPF, VLSM, BGP, serial, IGRP, Frame
Relay, ISDN, ISL, X.25, DDR, PSTN, PPP, VLANs, Ethernet, ATM
LANE–emulation, access lists, 802.10, FDDI, and transparent and
translational bridging
Introduction
xxix
To meet the CCNP requirements, you must be able to perform the
following:
Install and/or configure a network to increase bandwidth, quicken
network response times, and improve reliability and quality of service.
Maximize performance through campus LANs, routed WANs, and
remote access.
Improve network security.
Create a global intranet.
Provide access security to campus switches and routers.
Provide increased switching and routing bandwidth—end-to-end
resiliency services.
Provide custom queuing and routed priority services.
Friday, June 25, 2010
Molecule Self-Configuring Robots
This shape-changing bot is built of many simple modules which it can move around, allowing it to adapt to different tasks and build 3-dimensional structures. Click to enlarge.
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