1. Network Fundamentals Part 1 CS 1 Rick Graziani Cabrillo College

2. Rick Graziani graziani@cabrillo.edu2 What is networking? Communication! An interconnection of computers and other devices including: –Client computers –Servers (computers) –Network Devices Hubs and Switches Routers Firewall

3. Rick Graziani graziani@cabrillo.edu3 Most successful networking applications?

4. Rick Graziani graziani@cabrillo.edu4 What is in a network?

5. Rick Graziani graziani@cabrillo.edu5 What is a network? A computer network is a series of computers and other devices interconnected by communication paths. Computer networks include: LANs and WANs http://www.albany.edu

6. Rick Graziani graziani@cabrillo.edu6 Ethernet LANs

7. Rick Graziani graziani@cabrillo.edu7 LAN – Local Area Network LAN (Local Area Network) - A network connecting computers at a single site

8. Rick Graziani graziani@cabrillo.edu8 LAN – Local Area Network A LAN: –Operates within a limited geographical area –Controlled by local administration –Allows local users to: Share printers Access local file servers with software and data Access the Internet

9. Rick Graziani graziani@cabrillo.edu9 Ethernet LANs The most common LAN technology is Ethernet. Ethernet allows computers, printers, and other devices, “in the same network”, to be able to communicate. For devices to be able to communicate with each other over an Ethernet network, they must be configured with: –IP Address and Subnet Mask on the same network –What??? (We will discuss this shortly)

10. Rick Graziani graziani@cabrillo.edu10 Creating an Ethernet Network To start, your computer must have an Ethernet Network Interface Card (NIC). Ethernet NICs have an RJ-45 interface or port.

11. Rick Graziani graziani@cabrillo.edu11 Creating an Ethernet Network Hubs and Switches are used to connect computers, printers and other devices in the Ethernet LAN.

12. Rick Graziani graziani@cabrillo.edu12 Creating an Ethernet Network Ethernet cables, i.e. Cat-5 or Cat-6 cables (Category 5, Category 6) are used to connect computers to the hubs and switches. Cat-5 cable connects computer NIC to hub or switch.

13. Rick Graziani graziani@cabrillo.edu13 Creating an Ethernet Network

14. Rick Graziani graziani@cabrillo.edu14 Configuring IP (Internet Protocol)

15. Rick Graziani graziani@cabrillo.edu15 IP Configuration To communicate with other computers on your network you need to properly configure: –IP Address (of your computer) –Subnet Mask (of your computer) To communicate with computers outside your network you need to properly configure: –Default Gateway IP Address To be able to use domain names, like www.cabrillo.edu, instead of IP addresses you need to properly configure: –DNS (Domain Name System) Server IP Address

16. Rick Graziani graziani@cabrillo.edu16 IP Configuration: IP Address & Mask To communicate with other computers on your network you need to properly configure: –IP Address (of your computer) –Subnet Mask (of your computer) IP – Internet Protocol IP Address is the unique address of your computer on your network. Subnet Mask is used by your computer to figure out what network it belongs to. Analogy: –Name: RICKGRAZIANI –Mask: FFFFLLLLLLLL –The Mask tells us which part of RICKGRAZIANI is the first name (F) and which part is the last name (L). I am part of the 192.168.1.0 network!

17. Rick Graziani graziani@cabrillo.edu17 IP Configuration: Default Gateway To communicate with computers outside your network you need to properly configure: –Default Gateway IP Address

18. Rick Graziani graziani@cabrillo.edu18 IP Configuration: Default Gateway Default Gateway or Router: This is the device that connects your network to other networks, including the Internet. Switch ports that connect to computers on your LAN DSL or Cable Modem port that connects to your Internet Service Provider

19. Rick Graziani graziani@cabrillo.edu19 IP Configuration: Default Gateway Any information that needs to be sent to IP Addresses outside your network is sent to the Default Gateway or Router. To the Internet 192.168.1.10 192.168.1.1

20. Rick Graziani graziani@cabrillo.edu20 IP Configuration: DNS To be able to use domain names, like www.cabrillo.edu, instead of IP addresses you need to properly configure: –DNS (Domain Name System) Server IP Address 207.62.87.54

21. Rick Graziani graziani@cabrillo.edu21 IP Configuration: DNS You could use IP Addresses when accessing other computers, but we would rather use names (domain names).

22. Rick Graziani graziani@cabrillo.edu22 IP Configuration: DNS Computer networks only understand IP Addresses such as: –66.94.230.47 Computer networks do not understand domain names such as: –www.yahoo.com –A domain name is a name that is entered into a computer (e.g. as part of a website or other URL, or an email address) and then looked up in the global [Domain Name System] which informs the computer of the IP address(es) with that name. (Wikipedia.com) People are better with names than numbers, so we would rather use names when: –Accessing a web page: www.yahoo.com –Emailing a friend: Rick.Graziani@cabrillo.edu DNS (Domain Name System) servers (computers) are used to translate domain names to IP Addresses.

23. Rick Graziani graziani@cabrillo.edu23 IP Configuration: DNS Hey, 207.62.87.54, what is the IP Address for www.yahoo.com? It is 66.94.230.47 Yahoo Web Server Hey, 66.94.230.47, please send me your web page. Here, 192.168.1.10, here is my web page.

24. Rick Graziani graziani@cabrillo.edu24 IP Configuration: DNS The details of how DNS works. If your DNS server does not know the answer, it will find out for you.

25. Rick Graziani graziani@cabrillo.edu25 How do I view/edit this information on my computer?

26. Rick Graziani graziani@cabrillo.edu26 How do I view/edit this information on my computer? 1. Right click 2. Right click 3. TCP/IP, Properties Left click

27. Rick Graziani graziani@cabrillo.edu27 How do I view/edit this information on my computer?

28. Rick Graziani graziani@cabrillo.edu28 Setting the IP Configuration Information IP information can be configured: –Statically –Dynamically Using a DHCP (Dynamic Host Configuration Protocol) Server

29. Rick Graziani graziani@cabrillo.edu29 IP Configuration: Static Configuration Static configuration is when the user or administrator of the computer configures the IP Address, Subnet Mask, Default Gateway and DNS Server information.

30. Rick Graziani graziani@cabrillo.edu30 IP Configuration: Dynamic Configuration Dynamic configuration is when the IP Address, Subnet Mask, Default Gateway and DNS Server information is obtained automatically from a DHCP (Dynamic Host Configuration Protocol) Server.

31. Rick Graziani graziani@cabrillo.edu31 IP Configuration: Dynamic Configuration I’m booting up, if there is a DHCP Server out there, I need my IP Configuration Information! DHCP Server Here is your IP Address, Subnet Mask, IP Address for the Default Gateway (router), and IP Address for the DNS Server!

32. Rick Graziani graziani@cabrillo.edu32 The Internet and TCP/IP

33. Rick Graziani graziani@cabrillo.edu33 What is the Internet? The Internet was originally designed by DARPA (Defense Advanced Research Projects Agency) in response to the U.S.S.R. launching Sputnik, the first satellite. Out of this came the Internet, a way for computers to communicate from different parts of the world. These computers can be any type of computer using any type of operating system, as long as they are using the protocol TCP/IP.

34. Rick Graziani graziani@cabrillo.edu34 What is TCP/IP? What is a protocol? A protocol is nothing more than an agreement or rules to govern a way of communicating. The sender and receiver, and everyone in between, must agree on the rules, the protocol. The actual letter (data) is inside (encapsulated) the envelope.

35. Rick Graziani graziani@cabrillo.edu35 What is TCP/IP? What is a protocol? Protocol: An agreed form of communications.

36. Rick Graziani graziani@cabrillo.edu36 TCP/IP Transmission Control Protocol / Internet Protocol TCP/IP is a suite of protocols. IP (Internet Protocol) is used for sender and receiver addressing. Every computer on the Internet or a network must have an IP address to communicate. Source IP Address: 192.168.1.10 Destination IP Address 66.94.230.47 This is known as an “IP Packet”

37. Rick Graziani graziani@cabrillo.edu37 Yahoo Web Server Source IP Address: 192.168.1.10 Destination IP Address: 66.94.230.47 Destination IP Address: 192.168.1.10 Source IP Address: 66.94.230.47 192.168.1.10 66.94.230.47 Inside envelope: Request for web page Inside envelope: Web page

38. Rick Graziani graziani@cabrillo.edu38 Pinging another computer (FYI)

39. Rick Graziani graziani@cabrillo.edu39 Connecting Networks with Routers The Internet, or simply the Net, is the publicly accessible worldwide system of interconnected computer networks. Routers are network devices that connect two or more networks together. Routers connect networks.

40. Rick Graziani graziani@cabrillo.edu40 Connecting Networks with Routers

41. Rick Graziani graziani@cabrillo.edu41 DSL or Cable Modem: No Router 204.180.205.1 Public Address Hacker can only get to public address and not private address DSL or Cable Modem Routers can help protect your DSL or Cable Modem Network.

42. Rick Graziani graziani@cabrillo.edu42 DSL or Cable Modem: With a Router The router is between your computer (LAN) and your DSL Modem. The router is between you and the Internet. Internet

43. Rick Graziani graziani@cabrillo.edu43 When using NAT (Network Address Translation, the Router helps hide your network from attackers. 204.180.205.1 Public Address 192.168.1.10 Private Address Hackers can only get to public addresses and not private addresses DSL or Cable Modem: With a Router Internet

44. Rick Graziani graziani@cabrillo.edu44 Networks: Bandwidth and Connections Local Area Networks DSL Cable Modem Leased Lines Modems

45. Rick Graziani graziani@cabrillo.edu45 Bandwidth Bandwidth - The amount of information that can flow through a network connection in a given period of time. Usually measured in bits per second (bps) –bps: bits per second –Kbps: thousands of bits per second –Mbps: millions of bits per second

46. Rick Graziani graziani@cabrillo.edu46 Bandwidth LANs: 10 Mbps or 100 Mbps (or more) Connection to ISP (Internet Service Provider) Note: Bandwidth depends up provider, location, and service plan. DSL: –Download: 600 Kbps to 1.5 Mbps (or more) –Upload: 256 Kbps (or more) Cable Modem: –Download: 600 Kbps to 3.0 Mbps (or more) –Upload: 256 Kbps (or more) Telephone Modem: –Up to 53 Kbps Leased Lines –T1: 1.5 Mbps –T3: 44.736 Mbps

47. Rick Graziani graziani@cabrillo.edu47 Connection to ISP: DSL DSL (digital subscriber line) is a very high-speed connection that uses the same wires as a regular telephone line.

48. Rick Graziani graziani@cabrillo.edu48 DSL: From HowStuffWorks.com Advantages of DSL: –You can leave your Internet connection open and still use the phone line for voice calls. –The speed is much higher than a regular modem –DSL doesn't necessarily require new wiring; it can use the phone line you already have. –The company that offers DSL will usually provide the modem as part of the installation. But there are disadvantages: –A DSL connection works better when you are closer to the provider's central office. –The connection is faster for receiving data than it is for sending data over the Internet. –The service is not available everywhere.

49. Rick Graziani graziani@cabrillo.edu49 Connection to ISP: Cable Modem A cable modem is a special type of modem that is designed to modulate a data signal over cable television infrastructure.

50. Rick Graziani graziani@cabrillo.edu50 Connection to ISP: Telephone Modem A telephone modem is used to modulate and demodulate (translate) between the digital signals of the computer and the analog signals over the telephone line. Maximum bandwidth is only 53 Kbps. Need separate phone line if you want to use the phone while connected to the Internet

51. IPv4 and IPv6 Addressing No handout

52. IPv4 32 bits or 4 bytes 4,200,000,000 possible addressable nodes 4 billion possible addresses

53. 53 Who assigns IP Network Addresses? Internet Assigned Numbers Authority (IANA) (http://www.iana.net) is the master holder of the IP addresses. Today, the remaining IPv4 address space has been allocated to various other registries to manage for particular purposes or for regional areas. –Regional Internet Registries (RIRs)

54. 54 Regional Internet Registries (RIR) The 5 Regional Internet Registries (RIRs) are: –AfriNIC (African Network Information Centre) - Africa Region http://www.afrinic.net –APNIC (Asia Pacific Network Information Centre) - Asia/Pacific Region http://www.apnic.net –ARIN (American Registry for Internet Numbers) - North America Region http://www.arin.net –LACNIC (Regional Latin-American and Caribbean IP Address Registry) - Latin America and some Caribbean Islands http://www.lacnic.net –RIPE NCC (Reseaux IP Europeans) - Europe, the Middle East, and Central Asia http://www.ripe.net

55. 55 Most companies or organizations obtain their IPv4 address blocks from an ISP (Internet Service Provider). ISP (Internet Service Providers)

56. 56 Private IPv4 Addresses In early 1990’s IANA and IETF recognized that the we were running out of IPv4 addresses. Long term solution: IPv6 Short Term solution: –Private Addresses and Network Address Translation (NAT)

57. 57 Private IPv4 Addresses Private Addresses –10.0.0.0 to 10.255.255.255 (10.0.0.0 /8) –172.16.0.0 to 172.31.255.255 (172.16.0.0 /12) –192.168.0.0 to 192.168.255.255 (192.168.0.0 /16) The addresses will not be routed in the Internet –Need NAT (Network Address Translation)

58. Rick Graziani graziani@cabrillo.edu58 NAT – Network Address Translation PAT – Port Address Translation Private AddressesPublic Address

59. Monday, January 31, 2011 IANA allocated two blocks of IPv4 address space to APNIC, the RIR for the Asia Pacific region (39/8 and 106/8) IANA has no more IPv4 network addresses to allocate RIR’s Remaining IPv4 addresses

60.  IPv6 addresses are 128-bit addresses represented in:  Eight 16-bit segments or “hextets” (not a formal term)  Hexadecimal (non-case sensitive) between 0000 and FFFF  Separated by colons One Hex digit = 4 bits 2001:0DB8:AAAA:1111:0000:0000:0000:0100/64 2001 : 0DB8 : AAAA : 1111 : 0000 : 0000 : 0000 : 0100 16 bits

61.  How many addresses does 128 bits give us?  340 undecillion addesses or …  340 trillion trillion trillion addresses or …  “IPv6 could provide each and every square micrometer of the earth’s surface with 5,000 unique addresses. Micrometer = 0.001 mm or 0.000039 inches” or….  “A string of soccer balls would wrap around our universe 200 billion times!”

62. When will RIR’s run out of IPv4 Addresses? Rick Graziani graziani@cabrillo.edu62

63. Rick Graziani graziani@cabrillo.edu63 Why do we need to move to IPv6?

64. Network Fundamentals Part 1 CS 1 Rick Graziani Cabrillo College