ImPorTanT NetWorkIng QuEstiOnS Part3.

41. What is logical link control

One of two sub layers of the data link layer of OSI reference model, as defined by the IEEE 802 standard. This sub layer is responsible for maintaining the link between computers when they are sending data across the physical network connection.

42. Why should you care about the OSI Reference Model

It provides a framework for discussing network operations and design.

43. What is the difference between rout able and non- rout able protocols

Rout able protocols can work with a router and can be used to build large networks. Non-Rout able protocols are designed to work on small, local networks and cannot be used with a router.

44. What is MAU

In token Ring , hub is called Multi station Access Unit(MAU).

45. Explain 5-4-3 rule

In a Ethernet network, between any two points on the network, there can be no more than five network segments or four repeaters, and of those five segments only three of

segments can be populated.

46. What is the difference between TFTP and FTP application layer protocols

The Trivial File Transfer Protocol (TFTP) allows a local host to obtain files from a remote host but does not provide reliability or security. It uses the fundamental packet delivery services offered by UDP. The File Transfer Protocol (FTP) is the standard mechanism provided by TCP / IP for copying a file from one host to another. It uses the services offered by TCP and so is

reliable and secure. It establishes two connections (virtual circuits) between the hosts, one for data transfer and another for control information.

47. What is the range of addresses in the classes of internet addresses

Class A 0.0.0.0 - 127.255.255.255

Class B 128.0.0.0 - 191.255.255.255

Class C 192.0.0.0 - 223.255.255.255

Class D 224.0.0.0 - 239.255.255.255

Class E 240.0.0.0 - 247.255.255.255

48. What is the minimum and maximum length of the header in the TCP segment and IP datagram

The header should have a minimum length of 20 bytes and can have a maximum length of 60 bytes.

49. What is difference between ARP and RARP

The address resolution protocol (ARP) is used to associate the 32 bit IP address with the 48 bit physical address, used by a host or a router to find the physical address of

another host on its network by sending a ARP query packet that includes the IP address of the receiver. The reverse address resolution protocol (RARP) allows a host to discover its Internet address when it knows only its physical address.

50. What is ICMP

ICMP is Internet Control Message Protocol, a network layer protocol of the TCP/IP suite used by hosts and gateways to send notification of datagram problems back to the sender. It uses the echo test / reply to test whether a destination is reachable and responding. It also handles both control and error messages.

51. What are the data units at different layers of the TCP / IP protocol suite

The data unit created at the application layer is called a message, at the transport layer the data unit created is called either a segment or an user datagram, at the network layer the data unit created is called the datagram, at the data link layer the datagram is encapsulated in to a frame and finally transmitted as signals along the transmission media.

52. What is Project 802

It is a project started by IEEE to set standards that enable intercommunication between equipment from a variety of

manufacturers. It is a way for specifying functions of the physical layer, the data link layer and to some extent the network layer to allow for interconnectivity of major LAN

protocols.

It consists of the following:

802.1 is an internetworking standard for compatibility of different LANs and MANs across protocols.

802.2 Logical link control (LLC) is the upper sublayer of the data link layer which is non-architecture-specific, that is

remains the same for all IEEE-defined LANs.

Media access control (MAC) is the lower sublayer of the data link layer that contains some distinct modules each

carrying proprietary information specific to the LAN product

being used. The modules are Ethernet LAN (802.3), Token ring LAN (802.4), Token bus LAN (802.5).

802.6 is distributed queue dual bus (DQDB) designed to be used in MANs.

53. What is Bandwidth

Every line has an upper limit and a lower limit on the frequency of signals it can carry. This limited range is called the

bandwidth.

54. Difference between bit rate and baud rate.

Bit rate is the number of bits transmitted during one second whereas baud rate refers to the number of signal units per

second that are required to represent those bits.

baud rate = bit rate / N where N is no-of-bits represented by each signal shift.

55. What is MAC address

The address for a device as it is identified at the Media Access Control (MAC) layer in the network architecture. MAC

address is usually stored in ROM on the network adapter card and is unique.

56. What is attenuation

The degeneration of a signal over distance on a network cable is called attenuation.

57. What is cladding

A layer of a glass surrounding the center fiber of glass inside a fiber-optic cable.

58. What is RAID

A method for providing fault tolerance by using multiple hard disk drives.

59. What is NET BIOS and NETBEUI

NET BIOS is a programming interface that allows I/O requests to be sent to and received from a remote computer and it hides the networking hardware from applications.

NETBEUI is Net Bios extended user interface. A transport protocol designed by Microsoft and IBM for the use on small subnets.

60. What is re director

Re director is software that intercepts file or prints I/O requests and translates them into network requests. This comes under presentation layer.

Next part is coming soon...