1. Explain Proxy ARP
It is using a router to answer ARP requests. This will be done when the originating host believes that a destination is local, when in fact is lies beyond router.
2. Explain OSPF
It is an Internet routing protocol that scales well, can route traffic along multiple paths, and uses knowledge of an Internet's topology to make accurate routing decisions.
3. Explain Kerberos
It is an authentication service developed at the Massachusetts Institute of Technology. Kerberos uses encryption to prevent intruders from discovering passwords and gaining unauthorized access to files.
4. Explain a Multi-homed Host
It is a host that has a multiple network interfaces and that requires multiple IP addresses is called as a Multi-homed Host.
5. Explain NVT (Network Virtual Terminal)
It is a set of rules defining a very simple virtual terminal interaction. The NVT is used in the start of a Telnet session.
6. Explain Gateway-to-Gateway protocol
It is a protocol formerly used to exchange routing information between Internet core routers.
7. Explain BGP (Border Gateway Protocol)
It is a protocol used to advertise the set of networks that can be reached with in an autonomous system. BGP enables this information to be shared with the autonomous system. This is newer than EGP (Exterior Gateway Protocol).
8. Explain autonomous system
It is a collection of routers under the control of a single administrative authority and that uses a common Interior Gateway Protocol.
9. Explain EGP (Exterior Gateway Protocol)
It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.
10. Explain IGP (Interior Gateway Protocol)
It is any routing protocol used within an autonomous system.
11. Explain passive topology
When the computers on the network simply listen and receive the signal, they are referred to as passive because they don’t amplify the signal in any way. Example for passive topology - linear bus.
12. What are the important topologies for networks
BUS topology:
In this each computer is directly connected to primary network cable in a single line.
Advantages:
Inexpensive, easy to install, simple to understand, easy to extend.
STAR topology:
In this all computers are connected using a central hub.
Advantages:
Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical problems.
RING topology:
In this all computers are connected in loop.
Advantages:
All computers have equal access to network media, installation can be simple, and signal does not degrade as much as in other topologies because each computer
regenerates it.
13. What are major types of networks and explain
Server-based network
Peer-to-peer network
Peer-to-peer network, computers can act as both servers sharing resources and as clients using the resources.
Server-based networks provide centralized control of network resources and rely on server computers to provide security and network administration
14. Explain Protocol Data Unit
The data unit in the LLC level is called the protocol data unit (PDU). The PDU contains of four fields a destination service access point (DSAP), a source service access point (SSAP), a control field and an information field. DSAP, SSAP are addresses used by the LLC to identify the protocol stacks on the receiving and sending machines that are generating and using the data. The control field specifies whether the PDU frame is a information frame (I - frame) or a supervisory frame (S - frame) or a unnumbered frame (U - frame).
15. Explain difference between baseband and broadband transmission
In a baseband transmission, the entire bandwidth of the cable is consumed by a single signal. In broadband transmission, signals are sent on multiple frequencies, allowing multiple signals to be sent simultaneously.
16. What are the possible ways of data exchange
(i) Simplex (ii) Half-duplex (iii) Full-duplex.
17. What are the types of Transmission media
Signals are usually transmitted over some transmission media that are broadly classified in to two categories.
Guided Media:
These are those that provide a conduit from one device to another that include twisted-pair, coaxial cable and fiber-optic cable. A signal traveling along any of these media is directed and is contained by the physical limits of the medium. Twisted-pair and coaxial cable use metallic that accept
and transport signals in the form of electrical current. Optical fiber is a glass or plastic cable that accepts and transports signals in the form of light.
Unguided Media:
This is the wireless media that transport electromagnetic waves without using a physical conductor. Signals are broadcast either through air. This is done through radio communication, satellite communication and cellular telephony.
18. Explain point-to-point protocol
A communications protocol used to connect computers to remote networking services including Internet service providers.
19. What are the two types of transmission technology available
(i) Broadcast and (ii) point-to-point
20. Difference between the communication and transmission.
Transmission is a physical movement of information and concern issues like bit polarity, synchronization, clock etc. Communication means the meaning full exchange of information between two communication media.
21. Explain Mail Gateway
It is a system that performs a protocol translation between different electronic mail delivery protocols.
22. Explain wide-mouth frog
Wide-mouth frog is the simplest known key distribution center (KDC) authentication protocol.
23. What are Digrams and Trigrams
The most common two letter combinations are called as digrams. e.g. th, in, er, re and an. The most common three letter combinations are called as trigrams. e.g. the, ing, and, and ion.
24. Explain silly window syndrome
It is a problem that can ruin TCP performance. This problem occurs when data are passed to the sending TCP entity in large blocks, but an interactive application on the receiving side reads 1 byte at a time.
25. Explain region
When hierarchical routing is used, the routers are divided into what we call regions, with each router knowing all the details about how to route packets to destinations within its own region, but knowing nothing about the internal structure of other regions.
26. Explain multicast routing
Sending a message to a group is called multicasting, and its routing algorithm is called multicast routing.
27. Explain traffic shaping
One of the main causes of congestion is that traffic is often busy. If hosts could be made to transmit at a uniform rate, congestion would be less common. Another open loop method to help manage congestion is forcing the packet to be transmitted at a more predictable rate. This is called traffic shaping.
28. Explain packet filter
Packet filter is a standard router equipped with some extra functionality. The extra functionality allows every incoming or outgoing packet to be inspected. Packets meeting some criterion are forwarded normally. Those that fail the test are dropped.
29. Explain virtual path
Along any transmission path from a given source to a given destination, a group of virtual circuits can be grouped together into what is called path.
30. Explain virtual channel
Virtual channel is normally a connection from one source to one destination, although multicast connections are also permitted. The other name for virtual channel is virtual circuit.
31. Explain logical link control
One of two sublayers of the data link layer of OSI reference model, as defined by the IEEE 802 standard. This sublayer is responsible for maintaining the link between computers when they are sending data across the physical network connection.
32. Why should you care about the OSI Reference Model
It provides a framework for discussing network operations and design.
33. Explain the difference between routable and non- routable protocols
Routable protocols can work with a router and can be used to build large networks. Non-Routable protocols are designed to work on small, local networks and cannot be used with a router
34. Explain MAU
In token Ring , hub is called Multistation Access Unit(MAU).
35. 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.
36. Explain 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.
37. Explain 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
38. Explain 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.
39. Explain 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.
40. Explain 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.
41. 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.
42. Explain 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.
43. Explain 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.
44. 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.
45. Explain 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.
46. Explain attenuation
The degeneration of a signal over distance on a network cable is called attenuation.
47. Explain cladding
A layer of a glass surrounding the center fiber of glass inside a fiber-optic cable.
48. Explain RAID
A method for providing fault tolerance by using multiple hard disk drives.
49. Explain NETBIOS and NETBEUI
NETBIOS 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 NetBIOS extended user interface. A transport protocol designed by microsoft and IBM for the use on small subnets.
50. Explain redirector
Redirector is software that intercepts file or prints I/O requests and translates them into network requests. This comes under presentation layer.
51. What is meant by Middleware?
Middleware is a distributed software needed to support interaction between clients and servers. In short, it is the software that is in the middle of the Client/Server systems and it acts as a bridge between the clients and servers. It starts with the API set on the client side that is used to invoke a service and it covers the transmission of the request over the network and the resulting response.
It neither includes the software that provides the actual service - that is in the servers domain nor the user interface or the application login - that's in clients domain.
52. What are the functions of the typical server program?
It waits for client-initiated requests. Executes many requests at the same time. Takes care of VIP clients first. Initiates and runs background task activity. Keeps running. Grown bigger and faster.
53. What is meant by Symmentric Multiprocessing (SMP)?
It treats all processors as equal. Any processor can do the work of any other processor. Applications are divided into threads that can run concurrently on any available processor. Any processor in the pool can run the OS kernel and execute user-written threads.
54. What are Service-specific middleware?
It is needed to accomplish a particular Client/Server type of services which includes:-
• Database specific middleware
• OLTP specific middleware
• Groupware specific middleware
• Object specific middleware
• Internet specific middleware and
• System management specific middleware.
55. What are General Middleware?
It includes the communication stacks, distributed directories, authentication services, network time, RPC, Queuing services along with the network OS extensions such as the distributed file and print services.
56. What is meant by Asymmetric Multiprocessing (AMP)?
It imposses hierarchy and a division of labour among processors. Only one designated processor, the master, controls (in a tightly coupled arrangement) slave processors dedicated to specific functions.
57. What is OLTP?
In the transaction server, the client component usually includes GUI and the server components usually consists of SQL transactions against a database. These applications are called OLTP (Online Transaction Processing) OLTP Applications typically,
Receive a fixed set of inputs from remote clients. Perform multiple pre-compiled SQL comments against a local database. Commit the work and Return a fixed set of results.
58. What is meant by 3-Tier architecture?
In 3-tier Client/Server systems, the application logic (or process) lives in the middle tier and it is separated from the data and the user interface. In theory, the 3-tier Client/Server systems are more scalable, robust and flexible.
Example: TP monitor, Web.
59. What is meant by 2-Tier architecture?
In 2-tier Client/Server systems, the application logic is either burried inside the user interface on the client or within the database on the server.
Example: File servers and Database servers with stored procedures.
60. What is Load balancing?
If the number of incoming clients requests exceeds the number of processes in a server class, the TP Monitor may dynamically start new ones and this is called Load balancing.
61. What is Beaconing
The process that allows a network to self-repair networks problems. The stations on the network notify the other stations on the ring when they are not receiving the transmissions. Beaconing is used in Token ring and FDDI networks.
62. What is terminal emulation, in which layer it comes
Telnet is also called as terminal emulation. It belongs to application layer.
63. What is frame relay, in which layer it comes
Frame relay is a packet switching technology. It will operate in the data link layer.
64. What do you meant by "triple X" in Networks
The function of PAD (Packet Assembler Disassembler) is described in a document known as X.3. The standard protocol has been defined between the terminal and the PAD, called X.28; another standard protocol exists between hte PAD and the network, called X.29. Together, these three recommendations are often called "triple X"
65. What is SAP
Series of interface points that allow other computers to communicate with the other layers of network protocol stack.
66. What is subnet
A generic term for section of a large networks usually separated by a bridge or router.
67. What is Brouter
Hybrid devices that combine the features of both bridges and routers.
68. How Gateway is different from Routers
A gateway operates at the upper levels of the OSI model and translates information between two completely different network architectures or data formats.
69. What are the different type of networking / internetworking devices
Repeater:
Also called a regenerator, it is an electronic device that operates only at physical layer. It receives the signal in the
network before it becomes weak, regenerates the original bit pattern and puts the refreshed copy back in to the link.
Bridges:
These operate both in the physical and data link layers of LANs of same type. They divide a larger network in to smaller
segments. They contain logic that allow them to keep the traffic for each segment separate and thus are repeaters that relay a frame only the side of the segment containing the intended recipent and control congestion.
Routers:
They relay packets among multiple interconnected networks (i.e. LANs of different type). They operate in the physical,
data link and network layers. They contain software that enable them to determine which of the several possible paths is the best for a particular transmission.
Gateways:
They relay packets among networks that have different protocols (e.g. between a LAN and a WAN). They accept a
packet formatted for one protocol and convert it to a packet formatted for another protocol before forwarding it. They operate in all seven layers of the OSI model.
70. What is mesh network
A network in which there are multiple network links between computers to provide multiple paths for data to travel.
71. What are called Fat clients and Fat servers?
If the bulk of the application runs on the Client side, then it is Fat clients. It is used for decision support and personal software.
If the bulk of the application runs on the Server side, then it is Fat servers. It tries to minimize network interchanges by creating more abstract levels of services.
72. What is meant by Horizontal scaling and Vertical scaling?
Horizontal scaling means adding or removing client workstations with only a slight performance impact. Vertical scaling means migrating to a larger and faster server machine or multiservers.
73. What is Groupware server?
Groupware addresses the management of semi-structured information such as text, image, mail, bulletin boards and the flow of work. These Client/Server systems have people in direct contact with other people.
74. What are the two broad classes of middleware?
• General middleware
• Service-specific middleware.
75. What are the types of Servers?
• File servers
• Database servers Transaction servers Groupware servers
• Object servers Web servers.
76. What is a File server?
File servers are useful for sharing files across a network. With a file server, the client passes requests for file records over nerwork to file server.
77. What are the five major technologies that can be used to create Client/Server applications?
• Database Servers
• TP Monitors
• Groupware
• Distributed Objects
• Intranets.
78. What is Client/Server?
Clients and Servers are separate logical entities that work together over a network to accomplish a task. Many systems with very different architectures that are connected together are also called Client/Server.
79. List out the benefits obtained by using the Client/Server oriented TP Monitors?
• Client/Server applications development framework.
• Firewalls of protection.
• High availability.
• Load balancing.
• MOM integration.
• Scalability of functions.
• Reduced system cost.
80. What are the services provided by the Operating System?
Extended services - These are add-on modular software components that are layered on top of base servi
81.MIDI and MPEG are examples of what layer of the OSI seven layer model?
Presentation
82.What is the protocol number for UDP?
17
83.Which protocol is used for booting diskless workstations?
RARP
84.Which layer is responsible for putting 1s and 0s into a logical group?
Physical
85.What does 'P' mean when running a Trace?
Protocol unreachable
86.UDP works at which layer of the DOD model?
Host to Host
87.What is the default encapsulation of Netware 3.12?
802.2
88.Ping uses which Internet layer protocol?
ICMP
89.Which switching technology can reduce the size of a broadcast domain?
VLAN
90.What is the first step in data encapsulation?
User information is converted into data.
91.What is the protocol number for TCP?
6
92.What do you use the Aux port for?
Modem
93.Repeaters work at which layer of the OSI model?
Physical
94.WAN stands for which of the following?
Wide Area Network
95.What ISDN protocol specifies concepts, terminology, and services?
I
96.LAN stands for which of the following?
Local Are Network
97.DHCP stands for
Dynamic Host Configuration Protocol
98.What does the acronym ARP stand for?
Address Resolution Protocol
99.Which layer is responsible for identifying and establishing the availability of the intended communication partner?
Application.
100.Which OSI layer provides mechanical, electrical, procedural for activating, maintaining physical link?
Physical
It is using a router to answer ARP requests. This will be done when the originating host believes that a destination is local, when in fact is lies beyond router.
2. Explain OSPF
It is an Internet routing protocol that scales well, can route traffic along multiple paths, and uses knowledge of an Internet's topology to make accurate routing decisions.
3. Explain Kerberos
It is an authentication service developed at the Massachusetts Institute of Technology. Kerberos uses encryption to prevent intruders from discovering passwords and gaining unauthorized access to files.
4. Explain a Multi-homed Host
It is a host that has a multiple network interfaces and that requires multiple IP addresses is called as a Multi-homed Host.
5. Explain NVT (Network Virtual Terminal)
It is a set of rules defining a very simple virtual terminal interaction. The NVT is used in the start of a Telnet session.
6. Explain Gateway-to-Gateway protocol
It is a protocol formerly used to exchange routing information between Internet core routers.
7. Explain BGP (Border Gateway Protocol)
It is a protocol used to advertise the set of networks that can be reached with in an autonomous system. BGP enables this information to be shared with the autonomous system. This is newer than EGP (Exterior Gateway Protocol).
8. Explain autonomous system
It is a collection of routers under the control of a single administrative authority and that uses a common Interior Gateway Protocol.
9. Explain EGP (Exterior Gateway Protocol)
It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.
10. Explain IGP (Interior Gateway Protocol)
It is any routing protocol used within an autonomous system.
11. Explain passive topology
When the computers on the network simply listen and receive the signal, they are referred to as passive because they don’t amplify the signal in any way. Example for passive topology - linear bus.
12. What are the important topologies for networks
BUS topology:
In this each computer is directly connected to primary network cable in a single line.
Advantages:
Inexpensive, easy to install, simple to understand, easy to extend.
STAR topology:
In this all computers are connected using a central hub.
Advantages:
Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical problems.
RING topology:
In this all computers are connected in loop.
Advantages:
All computers have equal access to network media, installation can be simple, and signal does not degrade as much as in other topologies because each computer
regenerates it.
13. What are major types of networks and explain
Server-based network
Peer-to-peer network
Peer-to-peer network, computers can act as both servers sharing resources and as clients using the resources.
Server-based networks provide centralized control of network resources and rely on server computers to provide security and network administration
14. Explain Protocol Data Unit
The data unit in the LLC level is called the protocol data unit (PDU). The PDU contains of four fields a destination service access point (DSAP), a source service access point (SSAP), a control field and an information field. DSAP, SSAP are addresses used by the LLC to identify the protocol stacks on the receiving and sending machines that are generating and using the data. The control field specifies whether the PDU frame is a information frame (I - frame) or a supervisory frame (S - frame) or a unnumbered frame (U - frame).
15. Explain difference between baseband and broadband transmission
In a baseband transmission, the entire bandwidth of the cable is consumed by a single signal. In broadband transmission, signals are sent on multiple frequencies, allowing multiple signals to be sent simultaneously.
16. What are the possible ways of data exchange
(i) Simplex (ii) Half-duplex (iii) Full-duplex.
17. What are the types of Transmission media
Signals are usually transmitted over some transmission media that are broadly classified in to two categories.
Guided Media:
These are those that provide a conduit from one device to another that include twisted-pair, coaxial cable and fiber-optic cable. A signal traveling along any of these media is directed and is contained by the physical limits of the medium. Twisted-pair and coaxial cable use metallic that accept
and transport signals in the form of electrical current. Optical fiber is a glass or plastic cable that accepts and transports signals in the form of light.
Unguided Media:
This is the wireless media that transport electromagnetic waves without using a physical conductor. Signals are broadcast either through air. This is done through radio communication, satellite communication and cellular telephony.
18. Explain point-to-point protocol
A communications protocol used to connect computers to remote networking services including Internet service providers.
19. What are the two types of transmission technology available
(i) Broadcast and (ii) point-to-point
20. Difference between the communication and transmission.
Transmission is a physical movement of information and concern issues like bit polarity, synchronization, clock etc. Communication means the meaning full exchange of information between two communication media.
21. Explain Mail Gateway
It is a system that performs a protocol translation between different electronic mail delivery protocols.
22. Explain wide-mouth frog
Wide-mouth frog is the simplest known key distribution center (KDC) authentication protocol.
23. What are Digrams and Trigrams
The most common two letter combinations are called as digrams. e.g. th, in, er, re and an. The most common three letter combinations are called as trigrams. e.g. the, ing, and, and ion.
24. Explain silly window syndrome
It is a problem that can ruin TCP performance. This problem occurs when data are passed to the sending TCP entity in large blocks, but an interactive application on the receiving side reads 1 byte at a time.
25. Explain region
When hierarchical routing is used, the routers are divided into what we call regions, with each router knowing all the details about how to route packets to destinations within its own region, but knowing nothing about the internal structure of other regions.
26. Explain multicast routing
Sending a message to a group is called multicasting, and its routing algorithm is called multicast routing.
27. Explain traffic shaping
One of the main causes of congestion is that traffic is often busy. If hosts could be made to transmit at a uniform rate, congestion would be less common. Another open loop method to help manage congestion is forcing the packet to be transmitted at a more predictable rate. This is called traffic shaping.
28. Explain packet filter
Packet filter is a standard router equipped with some extra functionality. The extra functionality allows every incoming or outgoing packet to be inspected. Packets meeting some criterion are forwarded normally. Those that fail the test are dropped.
29. Explain virtual path
Along any transmission path from a given source to a given destination, a group of virtual circuits can be grouped together into what is called path.
30. Explain virtual channel
Virtual channel is normally a connection from one source to one destination, although multicast connections are also permitted. The other name for virtual channel is virtual circuit.
31. Explain logical link control
One of two sublayers of the data link layer of OSI reference model, as defined by the IEEE 802 standard. This sublayer is responsible for maintaining the link between computers when they are sending data across the physical network connection.
32. Why should you care about the OSI Reference Model
It provides a framework for discussing network operations and design.
33. Explain the difference between routable and non- routable protocols
Routable protocols can work with a router and can be used to build large networks. Non-Routable protocols are designed to work on small, local networks and cannot be used with a router
34. Explain MAU
In token Ring , hub is called Multistation Access Unit(MAU).
35. 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.
36. Explain 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.
37. Explain 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
38. Explain 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.
39. Explain 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.
40. Explain 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.
41. 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.
42. Explain 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.
43. Explain 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.
44. 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.
45. Explain 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.
46. Explain attenuation
The degeneration of a signal over distance on a network cable is called attenuation.
47. Explain cladding
A layer of a glass surrounding the center fiber of glass inside a fiber-optic cable.
48. Explain RAID
A method for providing fault tolerance by using multiple hard disk drives.
49. Explain NETBIOS and NETBEUI
NETBIOS 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 NetBIOS extended user interface. A transport protocol designed by microsoft and IBM for the use on small subnets.
50. Explain redirector
Redirector is software that intercepts file or prints I/O requests and translates them into network requests. This comes under presentation layer.
51. What is meant by Middleware?
Middleware is a distributed software needed to support interaction between clients and servers. In short, it is the software that is in the middle of the Client/Server systems and it acts as a bridge between the clients and servers. It starts with the API set on the client side that is used to invoke a service and it covers the transmission of the request over the network and the resulting response.
It neither includes the software that provides the actual service - that is in the servers domain nor the user interface or the application login - that's in clients domain.
52. What are the functions of the typical server program?
It waits for client-initiated requests. Executes many requests at the same time. Takes care of VIP clients first. Initiates and runs background task activity. Keeps running. Grown bigger and faster.
53. What is meant by Symmentric Multiprocessing (SMP)?
It treats all processors as equal. Any processor can do the work of any other processor. Applications are divided into threads that can run concurrently on any available processor. Any processor in the pool can run the OS kernel and execute user-written threads.
54. What are Service-specific middleware?
It is needed to accomplish a particular Client/Server type of services which includes:-
• Database specific middleware
• OLTP specific middleware
• Groupware specific middleware
• Object specific middleware
• Internet specific middleware and
• System management specific middleware.
55. What are General Middleware?
It includes the communication stacks, distributed directories, authentication services, network time, RPC, Queuing services along with the network OS extensions such as the distributed file and print services.
56. What is meant by Asymmetric Multiprocessing (AMP)?
It imposses hierarchy and a division of labour among processors. Only one designated processor, the master, controls (in a tightly coupled arrangement) slave processors dedicated to specific functions.
57. What is OLTP?
In the transaction server, the client component usually includes GUI and the server components usually consists of SQL transactions against a database. These applications are called OLTP (Online Transaction Processing) OLTP Applications typically,
Receive a fixed set of inputs from remote clients. Perform multiple pre-compiled SQL comments against a local database. Commit the work and Return a fixed set of results.
58. What is meant by 3-Tier architecture?
In 3-tier Client/Server systems, the application logic (or process) lives in the middle tier and it is separated from the data and the user interface. In theory, the 3-tier Client/Server systems are more scalable, robust and flexible.
Example: TP monitor, Web.
59. What is meant by 2-Tier architecture?
In 2-tier Client/Server systems, the application logic is either burried inside the user interface on the client or within the database on the server.
Example: File servers and Database servers with stored procedures.
60. What is Load balancing?
If the number of incoming clients requests exceeds the number of processes in a server class, the TP Monitor may dynamically start new ones and this is called Load balancing.
61. What is Beaconing
The process that allows a network to self-repair networks problems. The stations on the network notify the other stations on the ring when they are not receiving the transmissions. Beaconing is used in Token ring and FDDI networks.
62. What is terminal emulation, in which layer it comes
Telnet is also called as terminal emulation. It belongs to application layer.
63. What is frame relay, in which layer it comes
Frame relay is a packet switching technology. It will operate in the data link layer.
64. What do you meant by "triple X" in Networks
The function of PAD (Packet Assembler Disassembler) is described in a document known as X.3. The standard protocol has been defined between the terminal and the PAD, called X.28; another standard protocol exists between hte PAD and the network, called X.29. Together, these three recommendations are often called "triple X"
65. What is SAP
Series of interface points that allow other computers to communicate with the other layers of network protocol stack.
66. What is subnet
A generic term for section of a large networks usually separated by a bridge or router.
67. What is Brouter
Hybrid devices that combine the features of both bridges and routers.
68. How Gateway is different from Routers
A gateway operates at the upper levels of the OSI model and translates information between two completely different network architectures or data formats.
69. What are the different type of networking / internetworking devices
Repeater:
Also called a regenerator, it is an electronic device that operates only at physical layer. It receives the signal in the
network before it becomes weak, regenerates the original bit pattern and puts the refreshed copy back in to the link.
Bridges:
These operate both in the physical and data link layers of LANs of same type. They divide a larger network in to smaller
segments. They contain logic that allow them to keep the traffic for each segment separate and thus are repeaters that relay a frame only the side of the segment containing the intended recipent and control congestion.
Routers:
They relay packets among multiple interconnected networks (i.e. LANs of different type). They operate in the physical,
data link and network layers. They contain software that enable them to determine which of the several possible paths is the best for a particular transmission.
Gateways:
They relay packets among networks that have different protocols (e.g. between a LAN and a WAN). They accept a
packet formatted for one protocol and convert it to a packet formatted for another protocol before forwarding it. They operate in all seven layers of the OSI model.
70. What is mesh network
A network in which there are multiple network links between computers to provide multiple paths for data to travel.
71. What are called Fat clients and Fat servers?
If the bulk of the application runs on the Client side, then it is Fat clients. It is used for decision support and personal software.
If the bulk of the application runs on the Server side, then it is Fat servers. It tries to minimize network interchanges by creating more abstract levels of services.
72. What is meant by Horizontal scaling and Vertical scaling?
Horizontal scaling means adding or removing client workstations with only a slight performance impact. Vertical scaling means migrating to a larger and faster server machine or multiservers.
73. What is Groupware server?
Groupware addresses the management of semi-structured information such as text, image, mail, bulletin boards and the flow of work. These Client/Server systems have people in direct contact with other people.
74. What are the two broad classes of middleware?
• General middleware
• Service-specific middleware.
75. What are the types of Servers?
• File servers
• Database servers Transaction servers Groupware servers
• Object servers Web servers.
76. What is a File server?
File servers are useful for sharing files across a network. With a file server, the client passes requests for file records over nerwork to file server.
77. What are the five major technologies that can be used to create Client/Server applications?
• Database Servers
• TP Monitors
• Groupware
• Distributed Objects
• Intranets.
78. What is Client/Server?
Clients and Servers are separate logical entities that work together over a network to accomplish a task. Many systems with very different architectures that are connected together are also called Client/Server.
79. List out the benefits obtained by using the Client/Server oriented TP Monitors?
• Client/Server applications development framework.
• Firewalls of protection.
• High availability.
• Load balancing.
• MOM integration.
• Scalability of functions.
• Reduced system cost.
80. What are the services provided by the Operating System?
Extended services - These are add-on modular software components that are layered on top of base servi
81.MIDI and MPEG are examples of what layer of the OSI seven layer model?
Presentation
82.What is the protocol number for UDP?
17
83.Which protocol is used for booting diskless workstations?
RARP
84.Which layer is responsible for putting 1s and 0s into a logical group?
Physical
85.What does 'P' mean when running a Trace?
Protocol unreachable
86.UDP works at which layer of the DOD model?
Host to Host
87.What is the default encapsulation of Netware 3.12?
802.2
88.Ping uses which Internet layer protocol?
ICMP
89.Which switching technology can reduce the size of a broadcast domain?
VLAN
90.What is the first step in data encapsulation?
User information is converted into data.
91.What is the protocol number for TCP?
6
92.What do you use the Aux port for?
Modem
93.Repeaters work at which layer of the OSI model?
Physical
94.WAN stands for which of the following?
Wide Area Network
95.What ISDN protocol specifies concepts, terminology, and services?
I
96.LAN stands for which of the following?
Local Are Network
97.DHCP stands for
Dynamic Host Configuration Protocol
98.What does the acronym ARP stand for?
Address Resolution Protocol
99.Which layer is responsible for identifying and establishing the availability of the intended communication partner?
Application.
100.Which OSI layer provides mechanical, electrical, procedural for activating, maintaining physical link?
Physical
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