A beginner-level , computer networking stuff :)

2. [email_address]

3. GNU Free Documentation License

4. Version 0.1

5. OK, but we are going for something different....

7. “Physical Connectivity” among two or more devices

10. MAN( Metropolitian Area Network ) ie spans entire city.

11. WAN( Wide Area Network ) ie connects different cities, states , countries .

13. NIC ( Network Interface Card ) : it “physically” attaches a computer to a network .

16. For LAN we use CAT5 or CAT6 cables with RJ-45 connector ( Registered Jack )

17. Ethernet NIC card & Ethernet Connector with RJ-45 connector

18. RJ-45 connector & Crimper

19. Hub & Switch

22. Command to find MAC & IP address is : “ifconfig”

24. Each NIC is programmed at factory with unique MAC. .

26. Bottom 24 bits: node id

28. http://www.coffer.com/mac_find/

31. 2. Private

33. Range : 0.x.y.z to 127.x.y.z

34. Total nodes in a network of type Class A is ( 2^7 )*(2^24-2)

36. Higher 2bits are “10”

37. Range : 128.x.y.z to 191.x.y.z

38. Total nodes in a network of type Class B is ( 2^14)*(2^16-2)

40. Higher 3 bits are “110”

41. Range : 192.x.y.z to 223.x.y.z

46. Range is (240).x.y.z to (253).x.y.z

48. ANS: 78.0.0.0 , 78.0.0.1 , 78.255.255.254 , 78.255.255.255 ( in that order )

49. “DBA” is used if packet has to be transmitted to all systems in a network.

50. Make all “host ID” bits as “1” .

52. ANS : 203.89.79.00 , 203.89.79.01 , 203.89.79.254 , 203.89.79.255

54. Used to send packet to all nodes within “same” network .

55. Till now all we saw was “2-level hierarchy”.

56. But what is actually used is “3-level heirarchy” , it has concept of “subnetting”.

58. 1.)10.0.0.0 to 10.255.255.255 OR

59. 2.)172.16.0.0 to 172.31.255.255 OR

60. 3.)192.168.0.0 to 192.168.255.255.

61. Can you guess the class-type of each ??

62. NOTE: 1.) has only 1 network , 2.) has max 16 networks & 3.) has max 256 networks .

64. Agent between public & private network.

65. Hides entire IP addr space behind single /group of IP addr.

67. For eg, they must be given IP addr , default route etc .

68. This could be done manually. But DHCP does this for us.

69. It is – Dynamic Host Control Protocol .

71. DHCP enabled on your computer means you are letting DHCP server assign a IP( from a defined range of nos. )

72. DHCP server assigns a device IP , subnet mask , default gateway .

74. Std technology for managing names of websites & Internet domains .

75. DNS server is like look-up table.

76. Can you think of something similar that we already use ??

78. All DNS servers are arranged in heirarchy .

79. cat /etc/resolv.conf

81. ifconfig eth0 down : disable network card

82. ifconfig eth0 up : enable network card

83. host moodle.coep.org.in : DNS test

84. traceroute www.whatismyip.com

85. tracepath www.whatismyip.com

87. ping moodle.coep.org.in : check connection

88. netstat -rn : ??

90. Try this : ssh [email_address]

91. Try this : scp document.pdf [email_address] : ( send file at home folder of student )

92. Several combinations for scp at : http://www.examplenow.com/scp/