Presentation Transcript

1. Discovering the InternetComplete Concepts and Techniques, Second Edition

   Chapter 6 Understanding Internet Technologies and Security
2. Objectives Discuss basic networking technologies Describe the infrastructure of the Internet, including network service providers, the TCP/IP stack, IP addresses, and the Domain Name System (DNS) Discuss GPS and identify wireless location-based services Chapter 6: Understanding Internet Technologies and Security
3. Objectives Explain the convergence of the Internet with telephony and conferencing Discuss internal and external network security threats, transactional risks, and virtual private networks Chapter 6: Understanding Internet Technologies and Security
4. Networking Basics A computer network connects two or more computers, printers, or other devices together with cables or wireless media allowing users to share Data Peripheral devices An Internet connection Chapter 6: Understanding Internet Technologies and Security
5. Networking Basics Local, Metropolitan, and Wide Area Networks Modern networks can be categorized by the physical area they cover Local area (home, office, or single building) Metropolitan area (region) Wide area (multiple cities or the world) Chapter 6: Understanding Internet Technologies and Security
6. Networking Basics Local Area Networks A local area network (LAN) supports users in a small geographical area Home Office Single building Several buildings, for example: a college campus Chapter 6: Understanding Internet Technologies and Security
7. Networking Basics Local Area Networks (cont'd) LANs are configured in one of two basic structures Peer-to-peer Client/server Peer-to-peer LAN 10 or fewer personal computers connected One or more of the computers may also have a printer, scanner, or external storage device Chapter 6: Understanding Internet Technologies and Security
8. Networking Basics Local Area Networks (cont'd) Peer-to-peer LAN (cont'd) Each node must have a network interface card (NIC) Each node may be connected to a single cable or may be connected at a common connection point using a hub Does not require a network operating system Chapter 6: Understanding Internet Technologies and Security
9. Networking Basics Local Area Networks (cont'd) Peer-to-peer LAN (cont'd) Users can access files stored on any computer Users can access any peripheral device connected to a computer on the network Attractive networking choice for home, small business, or other organization just getting started with networking Simple to configure Easy to operate Chapter 6: Understanding Internet Technologies and Security
10. Networking Basics Chapter 6: Understanding Internet Technologies and Security
11. Networking Basics Local Area Networks (cont'd) Client/Server Network Multiple personal computers or workstations (clients) One or more servers Other devices, such as printers Chapter 6: Understanding Internet Technologies and Security
12. Networking Basics Local Area Networks (cont'd) Client/Server Network (cont'd) Uses a network operating system to manage Data storage Printer access Communications Internet connections Security Network administration Examples include Windows 7, Windows Vista, UNIX, and Novell Open Enterprise Server Chapter 6: Understanding Internet Technologies and Security
13. Networking Basics Local Area Networks (cont'd) Client/Server Networks (cont'd) Advantages over a peer-to-peer network Supports shared data storage Provides network maintenance tools Promotes more efficient data backups Disadvantages compared to a peer-to-peer network More expensive More difficult to configure Requires more technical expertise to manage Chapter 6: Understanding Internet Technologies and Security
14. Networking Basics Chapter 6: Understanding Internet Technologies and Security
15. Networking Basics Chapter 6: Understanding Internet Technologies and Security
16. Networking Basics Metropolitan Area Networks (MANs) Connects clients and servers in a region that is larger than a single office or building Multiple buildings across a city, multiple educational, research, or government facilities across a state Chapter 6: Understanding Internet Technologies and Security
17. Networking Basics Wide Area Networks (WANs) Cover a very wide geographical area Can be a single network or multiple connected LANs located across the country or around the world Most WANs are private, corporately owned networks The Internet is the world’s largest public WAN Chapter 6: Understanding Internet Technologies and Security
18. Networking Basics Network Topologies, Access Methods, and Transmission Media Physical topology – the layout in which a network’s computers, printers, and other devices are arranged Access method – how data is transmitted from one node to another Transmission media – physical or wireless communication media that carry transmissions These three characteristics define the throughput Chapter 6: Understanding Internet Technologies and Security
19. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Three basic LAN physical topologies Bus Ring Star Many modern LANs use a hybrid physical topology that combines some elements of these three topologies Chapter 6: Understanding Internet Technologies and Security
20. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Bus topology connects all nodes on a peer-to-peer LAN with a single cable called a bus Chapter 6: Understanding Internet Technologies and Security
21. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Bus topology (cont'd) Only one transmission allowed at a time A node announces to the entire network when it is ready to send a transmission All nodes except the destination node ignore the transmission If a problem occurs with the bus, the entire network becomes inoperable Chapter 6: Understanding Internet Technologies and Security
22. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Ring topology connects each node to the next node via a single circle of cable Chapter 6: Understanding Internet Technologies and Security
23. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Ring topology (cont'd) A transmission moves from node to node around the circle clockwise Each node accepts any data addressed to it and then forwards the transmission to the next node Failure of one node can affect all the nodes following it Chapter 6: Understanding Internet Technologies and Security
24. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Star topology connects each node to a central device, such as a hub or switch Chapter 6: Understanding Internet Technologies and Security
25. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Star topology (cont'd) A transmission passes from the originating node, through the hub, directly to the destination node Failure of a single node does not make the entire network inoperable Chapter 6: Understanding Internet Technologies and Security
26. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Access Method Ethernet – a node wanting to transmit data first must determine whether or not another node is transmitting If yes – waits a short period of time and tests again If no – transmits Networks using a bus or star physical topology commonly use the Ethernet access method Transmits data from 10 Mbps – 100 Mbps High-speed networks might use Gigabit Ethernet, which can transmit data at 1, 10, 40, or 100 Gigabits Chapter 6: Understanding Internet Technologies and Security
27. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Access Method (cont'd) Token ring – uses a token-passing method in which the network has a single token that moves in a clockwise circle from node to node Node that has the token can add data and the address of the destination node and then sends token on to the next node Destination node receives the token, accepts the data, and then issues a free (unused) token and sends it on to the next node Chapter 6: Understanding Internet Technologies and Security
28. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Transmission Media Physical transmission media Coaxial cable Twisted-pair cable Fiber-optic cable Twisted-pair cable commonly used as a LAN transmission medium Fiber-optic cable commonly used as a MAN or WAN transmission medium Chapter 6: Understanding Internet Technologies and Security
29. Networking Basics Chapter 6: Understanding Internet Technologies and Security
30. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Wireless transmission media Infrared (IR) transmissions use line-of-sight infrared light-wave signals Radio frequency (RF) transmissions use broadcast radio waves to transmit data over short distances Bluetooth is a short-range RF technology Chapter 6: Understanding Internet Technologies and Security
31. Networking Basics Chapter 6: Understanding Internet Technologies and Security
32. Networking Basics Network Topologies, Access Methods, and Transmission Media (cont'd) Wireless transmission media (cont'd) Wireless Fidelity (Wi-Fi) 802.11 standard specifies the radio frequencies and data transmission speeds for wireless networks Chapter 6: Understanding Internet Technologies and Security
33. Networking Basics Connectivity Hardware and Software Hardware connectivity devices connect nodes on the same network, network segments, or multiple networks Hubs Bridges Data switches Routers Gateways (hardware or software) Chapter 6: Understanding Internet Technologies and Security
34. Networking Basics Connectivity Hardware and Software (cont'd) Hubs, Bridges, and Data Switches Hubs – inexpensive hardware device used to connect nodes on the same network Bridges – connects two segments on the same LAN or two LANs Data switches – intelligent device that filters and forwards data packets to network segments Chapter 6: Understanding Internet Technologies and Security
35. Networking Basics Connectivity Hardware and Software (cont'd) Routers Specialized computers that connect LAN segments, two LANs, or multiple LANs on a WAN Determines the best route for packets Internet routers are complex, fast devices that send packets from one router to another in a series of “hops” until they reach their destination network Use the Tracert utility to trace router “hops” Chapter 6: Understanding Internet Technologies and Security
36. Networking Basics Chapter 6: Understanding Internet Technologies and Security
37. Networking Basics Connectivity Hardware and Software (cont'd) Gateways Hardware or software used to connect two or more networks or network segments that use different packet formatting, communication protocols, and access methods Chapter 6: Understanding Internet Technologies and Security
38. Networking Basics Chapter 6: Understanding Internet Technologies and Security
39. Internet Infrastructure Network service providers (NSPs) TCP/IP stack IP addresses Domain Name System Chapter 6: Understanding Internet Technologies and Security
40. Internet Infrastructure Network Service Providers Provide the public and private network infrastructure for the Internet Verizon, AT&T, Sprint, and others Network access points (NAPs) – connection points on the Internet backbone where multiple NSP networks come together to exchange traffic MAE – a specific type of high-speed Ethernet NAP located in three regional areas Peering – the exchange of Internet traffic and router information between NSPs and ISPs at public or private connection points Chapter 6: Understanding Internet Technologies and Security
41. Internet Infrastructure Chapter 6: Understanding Internet Technologies and Security
42. Internet Infrastructure TCP/IP Stack TCP/IP Stack – de facto set of standard Internet protocols for network communications TCP, IP, HTTP, POP3, IMAP4, FTP and so forth IP Addresses The unique address of each node on a network 32-bit number made up of four 8-bit numbers or octets separated by periods, such as 202.78.173.12 Assigned based on network classes A-E Chapter 6: Understanding Internet Technologies and Security
43. Internet Infrastructure Classless Routing System CIDR allows network administrators to expand the number of network nodes assigned to an IP address Used extensively on the Internet Used in large private networks Chapter 6: Understanding Internet Technologies and Security
44. Internet Infrastructure Chapter 6: Understanding Internet Technologies and Security
45. Internet Infrastructure Domain Name System The DNS is a hierarchy of name servers used to resolve a registered and easy-to-remember text domain name with its equivalent IP address Twelve different organizations, such as VeriSign, NASA, the University of Maryland, and the University of Southern California, operate the root name servers from 13 IPv4 IP addresses and hundreds of root name server computers located around the world Chapter 6: Understanding Internet Technologies and Security
46. Internet Infrastructure Chapter 6: Understanding Internet Technologies and Security
47. Internet Infrastructure Chapter 6: Understanding Internet Technologies and Security
48. Location-Based Services and GPS Handheld wireless devices are used to communicate with friends, connect to the Internet, check your e-mail, download games, get driving instructions, or view other wireless Web content Chapter 6: Understanding Internet Technologies and Security
49. Location-Based Services and GPS Location-based services (LBS)are wireless services offered to customers based on their physical location E9-11 At the heart of this and other LBSs are the global positioning system (GPS) satellite network and receivers mounted in autos or placed in cell phones or other handheld devices Chapter 6: Understanding Internet Technologies and Security
50. Location-Based Services and GPS Chapter 6: Understanding Internet Technologies and Security
51. Internet Telephony and Web Conferencing Internet telephony Voice over IP (VoIP) Uses TCP/IP and packet switching to send voice transmissions over private or public IP network Telecommunications carriers combine digital and analog transmissions E-businesses, such as Vonage, offer digital telephony services Computer to computer calling using special software, such as Skype Chapter 6: Understanding Internet Technologies and Security
52. Internet Telephony and Web Conferencing Chapter 6: Understanding Internet Technologies and Security
53. Internet Telephony and Web Conferencing Chapter 6: Understanding Internet Technologies and Security
54. Internet Telephony and Web Conferencing A virtual meeting allows collaboration between participants, such as a group ofemployees, by allowing invitees to log on to their network and sign in to a meeting in which they communicate with each other as well as view, share, and work collaboratively on files Windows Meeting Space Videoconferencing sometimes involves hundreds or thousands of participants Web conferencing is a virtual meeting conducted using a browser and the Web Chapter 6: Understanding Internet Technologies and Security
55. Network Security Issues and Technologies Internal threats Security policies and procedures Authorized network access Data backup and restore Disaster recovery planning Chapter 6: Understanding Internet Technologies and Security
56. Network Security Issues and Technologies External threats Unauthorized network access Computer viruses Web page hacking Firewalls and proxy servers Internet filtering software Security audits Chapter 6: Understanding Internet Technologies and Security
57. Network Security Issues and Technologies Transactional risks Protecting and validating online transaction information Chapter 6: Understanding Internet Technologies and Security
58. Virtual Private Networks A private network uses a large public IP network, such as the Internet, to transmit its data Encrypted data and tunneling protocol are encapsulated inside regular IP packets which are routed over the public network At destination network, the IP protocol information is removed and the tunneling protocol transmits the data to its destination computer Chapter 6: Understanding Internet Technologies and Security
59. Virtual Private Networks Chapter 6: Understanding Internet Technologies and Security
60. Summary Discuss basic networking technologies Describe the infrastructure of the Internet, including network service providers, the TCP/IP stack, IP addresses, and the Domain Name System (DNS) Discuss GPS and identify wireless location-based services Chapter 6: Understanding Internet Technologies and Security
61. Summary Explain the convergence of the Internet with telephony and conferencing Discuss internal and external network security threats, transactional risks, and virtual private networks Chapter 6: Understanding Internet Technologies and Security
62. Chapter 6 Complete Chapter 6 Complete