Networking 101 Data Communications Systems …

1 Networking 101 data Communications SystemsFinal Exam study GuideProfessor Don ColtonIT 280 - Winter 2011 Brigham Young University HawaiiContents1 Target Skills .. Basic Skills .. Notation ..62 The URL .. Names .. IPv4 Addresses .. Bases .. Numbers .. Addressing .. Classful Addressing .. Masks .. Routing .. Addresses .. Classless Addressing .. Block Size .. Count .. Subnet .. Subnet .. Subnet .. 243 OSI 7-layer Model264 Power .. ping .. traceroute .. ipconfig .. nmap .. ssh .. telnet .. ftp .. wireshark .. 305 Home Router326 WiFi ( )357 Well Known Ports.

2 Secure Connections .. Firewalls .. Password Selection .. 398 Be The Printer Sharing .. File Sharing .. Ad Hoc Wireless Networking .. 439 Lab Activities44 Index45 Chapter 1 IntroductionNetworking 101 is a college-level introduction to data Communications andnetworking. It covers the information appropriate to an introductory one-semester (forty class hour) course in focus on target skills, concepts, and topics that are normally expectedof students who have passed such a course. We also cover the basic skillsand concepts that support these target is a substantial departure from approaches that work from a historicalaggregation of things that were taught since the early days of Networking . Itis, instead, a re-inventing of the subject matter, giving up some less usefultopics in favor of things that are more relevant at the introductory note that this booklet is currently (Feb 2011) under development, sonew sections may appear and existing sections may be revised.

3 Suggestionsare welcome: Target SkillsSo, whatistypically expected of students who have passed an introductorycourse in Networking ? What would your parents and friends expect you toknow?(a) Can you help me set up my home network? I don t understand all thesesettings.(b) Can you help me set up my wireless home network? Does it matter if I4 CHAPTER 1. INTRODUCTION5let my neighbors share it?(c) Can you help me with all these firewalls and things? It sounds like agood thing, but it just seems to get in the way, especially when I am gaming.(d) Can you help me share a printer with my roommates?(e) Can you help me share documents and files with my family?These target skills, sometimes called exit skills, are the skills that enablestudents overcome their own Networking problems and to solve networkingproblems for :Home Router: Students should be able to properly set up a homerouter.

4 This is covered in chapter 5 (page 32).Skill:WiFi: Students should be able to properly set up wireless includes channel selection, wep/wpa, ssid, and antenna is covered in chapter 6 (page 35).Skill:Security: Students should know what security they have and whetherthey need more. Includes password selection, firewalls, and issues with open-ing up ports for gaming or whatever. Does sharing your WiFi put you inany danger? This is covered in chapter 7 (page 37).Skill:Be The Server: Networks often involve the sharing of printer and can be done by adding network-ready printer or storage. But often itis done by sharing parts of existing computer Systems , such as their printeror hard drive. How this is done depends a lot on the operating system ofthe computer that will be doing the will address a few of these tasks in the context of Microsoft we will look at printer sharing, file sharing, and configuring adhoc wireless networks.

5 This is covered in chapter 8 (page 42). Basic SkillsThe target skills are things youalready knowyou don t know. You wantto learn of the target skills cannot simply be memorized. Instead, they mustbe understood. Almost immediately basic concepts come up like domainnames, WiFi network IDs, IP addresses, network masks, and 1. INTRODUCTION6 The basic skills and concepts are those other things you have to learn firstbefore you can be truly proficient in the target basic skills are things youdidn t knowyou would need to know. Youmay not know they even :Networks: Students should understand the following concepts: IPv4address, subnet mask, port, address classes ABC, MAC address, collisiondomains, what s a LAN, broadcast addresses. This is covered in chapter 2(page 7).

6 Skill:Basic Concepts: Understand the following concepts: OSI 7-layermodel, packets, frames, udp, tcp, arp, ports (21, 22, 25, 80, 443). I couldhave included this with Networks but I wanted the groupings to be of similarsize and it was getting kind of big. This is covered in chapter 3 (page 26).Skill:Power Tools: Students should be able to properly use these , ping, traceroute, ipconfig, nmap, ssh, telnet, ftp, and wire-shark. These are the tools of the trade and students should be either skilledor familiar with them. This is covered in chapter 4 (page 28). NotationThe following notation is used freqently in this book to quickly identifyimportant types of :This is a skill that should be :This is something that would be interesting or helpful to know, butyou are not expected to memorize :This is something that should be :This is a typical question that uses the :This is a correct answer for the question just givenA?

7 This is an explanation of how the answer could be 2 IPv4 For most people, the first exposure to the Internet comes in the form of aweb browser. It is a living newspaper. It is a window into the library of theworld. And it has its own cryptic way of finding content. It is called a information itself lives on a server. A server is another computer , some-where else in the world, that provides services to people like yourself. TheURL is the browser s way of finding that server and requesting the contentthat you a common name for the Internet. It refers specifically to thatpart of the Internet where web pages and web sites the whole collection of all web sites and other ser-vices (of which there are many) that are connected together in a world-widenetwork of resources and components.

8 It is much bigger than the web, butthe web is its most familiar The URLURL, pronounced as three separate letters, like you are ell, stands forUniversal Resource Locator. Another common term isURI, for UniversalResource Identifier. URI is actually more technically correct, but somehowURL seems to roll off the lips easier and has become the defacto name forweb URL consists of several parts. Let s look at 2. IPV48 URL is pretty standard. We will look at a more complicated :is the the domain the complete Protocolshttpis the is the language with which the browser will talk to the server. HTTP stands for Hyper Text Transport popular protocols you may see include these:https: hyper text transport protocol with : email address (and possibly more).

9 Ftp: file transport Domain the domain name. It is intended to identify a specificcomputer that contains or has access to the resources you is a whole system of domain names. The most popular set is calledthedot comdomain names. These are used by nearly every business thathas a presence on the domain names start withwww, which stands for World Wide is not a requirement, but it is probably the most familiar way to introducea URL, instead of saying http:// .The actual way that computers are identified on the Internet is by wayof something called anIP address. These are typically written as fournumbers connected by dots. For example, the IP addressof the computer that sits on my desk at the university where I will talk much more about IP addresses, starting in section (page10) 2.

10 IPV49 Numbers are a fine way for computers to find each other, but humans likewords instead. We see that in the numerous clever attempts to converttelephone numbers into words. Imagine 1-555-SAVE-NOW. Compare thatto 1-555-728-3669. Which one do you think is easier to remember? For meit is easier to dial the digits, but easier to remember the whole industry has grown up around the providing of domain are big business. And it makes it pretty easy to identify the businessor organization that you are visiting on the section??(page??) for more on the domain name does not matter with domain names. You can say or and it s all the same to the Paths/ an example of a speaking, the path is not required to have any special meaning.