Interview questions
Define Network?
A network is a set of devices connected by physical media links. A network
is recursively is a connection of two or more nodes by a physical link or two
or more networks connected by one or more nodes.
2. What is a Link?
At the lowest level, a network can consist of two or more computers directly
connected by some physical medium such as coaxial cable or optical fiber. Such
a physical medium is called as Link.
3. What is a node?
A network can consist of two or more computers directly connected by some
physical medium such as coaxial cable or optical fiber. Such a physical medium
is called as Links and the computer it connects is called as Nodes.
4. What is a gateway or Router?
A node that is connected to two or more networks is commonly called as
router or Gateway. It generally forwards message from one network to another.
5. What is point-point link?
If the physical links are limited to a pair of nodes it is said to be
point-point link.
6. What is Multiple Access?
If the physical links are shared by more than two nodes, it is said to be
Multiple Access.
7. What are the advantages of Distributed Processing?
a. Security/Encapsulationb. Distributed database
c. Faster Problem solving
d. Security through redundancy
e. Collaborative Processing
8. What are the criteria necessary for an effective and
efficient network?
a. PerformanceIt can be measured in many ways, including transmit time and response time. b. Reliability
It is measured by frequency of failure, the time it takes a link to recover from a failure, and the network's robustness.
c. Security
Security issues includes protecting data from unauthorized access and virues.
9. Name the factors that affect the performance of the
network?
a. Number of Usersb. Type of transmission medium
c. Hardware
d. Software
10. Name the factors that affect the reliability of the
network?
a. Frequency of failureb. Recovery time of a network after a failure
11. Name the factors that affect the security of the
network?
a. Unauthorized Accessb. Viruses
12. What is Protocol?
A protocol is a set of rules that govern all aspects of information
communication.
13. What are the key elements of protocols?
The key elements of protocols area. Syntax
It refers to the structure or format of the data, that is the order in which they are presented.
b. Semantics
It refers to the meaning of each section of bits.
c. Timing
Timing refers to two characteristics: When data should be sent and how fast they can be sent.
14. What are the key design issues of a computer
Network?
a. Connectivityb. Cost-effective Resource Sharing
c. Support for common Services
d. Performance
15. Define Bandwidth and Latency?
Network performance is measured in Bandwidth (throughput) and Latency
(Delay). Bandwidth of a network is given by the number of bits that can be
transmitted over the network in a certain period of time. Latency corresponds
to how long it t5akes a message to travel from one end off a network to the
other. It is strictly measured in terms of time.
16. Define Routing?
The process of determining systematically hoe to forward messages toward the
destination nodes based on its address is called routing.
17. What is a peer-peer process?
The processes on each machine that communicate at a given layer are called
peer-peer process.
18. When a switch is said to be congested?
It is possible that a switch receives packets faster than the shared link
can accommodate and stores in its memory, for an extended period of time, then
the switch will eventually run out of buffer space, and some packets will have
to be dropped and in this state is said to congested state.
19. What is semantic gap?
Defining a useful channel involves both understanding the applications
requirements and recognizing the limitations of the underlying technology. The
gap between what applications expects and what the underlying technology can
provide is called semantic gap.
20. What is Round Trip Time?
The duration of time it takes to send a message from one end of a network to
the other and back, is called RTT.
21. Define the terms Unicasting, Multiccasting and
Broadcasting?
If the message is sent from a source to a single destination node, it is
called Unicasting.If the message is sent to some subset of other nodes, it is called Multicasting.
If the message is sent to all the m nodes in the network it is called Broadcasting.
22. What is Multiplexing?
Multiplexing is the set of techniques that allows the simultaneous
transmission of multiple signals across a single data link.
23. Name the categories of Multiplexing?
a. Frequency Division Multiplexing (FDM)b. Time Division Multiplexing (TDM)
i. Synchronous TDM
ii. ASynchronous TDM Or Statistical TDM.
c. Wave Division Multiplexing (WDM)
24. What is FDM?
FDM is an analog technique that can be applied when the bandwidth of a link
is greater than the combined bandwidths of the signals to be transmitted.
25. What is WDM?
WDM is conceptually the same as FDM, except that the multiplexing and
demultiplexing involve light signals transmitted through fiber optics channel.
26. What is TDM?
TDM is a digital process that can be applied when the data rate capacity of
the transmission medium is greater than the data rate required by the sending
and receiving devices.
27. What is Synchronous TDM?
In STDM, the multiplexer allocates exactly the same time slot to each device
at all times, whether or not a device has anything to transmit.
28. List the layers of OSI
a. Physical Layerb. Data Link Layer
c. Network Layer
d. Transport Layer
e. Session Layer
f. Presentation Layer
g. Application Layer
29. Which layers are network support layers?
a. Physical Layerb. Data link Layer and
c. Network Layers
30. Which layers are user support layers?
a. Session Layerb. Presentation Layer and
c. Application Layer
31. Which layer links the network support layers and
user support layers?
The Transport layer links the network support layers and user support
layers.
32. What are the concerns of the Physical Layer?
Physical layer coordinates the functions required to transmit a bit stream
over a physical medium.a. Physical characteristics of interfaces and media
b. Representation of bits
c. Data rate
d. Synchronization of bits
e. Line configuration
f. Physical topology
g. Transmission mode
33. What are the responsibilities of Data Link Layer?
The Data Link Layer transforms the physical layer, a raw transmission
facility, to a reliable link and is responsible for node-node delivery.a. Framing
b. Physical Addressing
c. Flow Control
d. Error Control
e. Access Control
34. What are the responsibilities of Network Layer?
The Network Layer is responsible for the source-to-destination delivery of
packet possibly across multiple networks (links).a. Logical Addressing
b. Routing
35. What are the responsibilities of Transport Layer?
The Transport Layer is responsible for source-to-destination delivery of the
entire message.a. Service-point Addressing
b. Segmentation and reassembly
c. Connection Control
d. Flow Control
e. Error Control
36. What are the responsibilities of Session Layer?
The Session layer is the network dialog Controller. It establishes,
maintains and synchronizes the interaction between the communicating systems.a. Dialog control
b. Synchronization
37. What are the responsibilities of Presentation Layer?
The Presentation layer is concerned with the syntax and semantics of the
information exchanged between two systems.a. Translation
b. Encryption
c. Compression
38. What are the responsibilities of Application Layer?
The Application Layer enables the user, whether human or software, to access
the network. It provides user interfaces and support for services such as
e-mail, shared database management and other types of distributed information
services.a. Network virtual Terminal
b. File transfer, access and Management (FTAM)
c. Mail services
d. Directory Services
39. What are the two classes of hardware building
blocks?
Nodes and Links.
40. What are the different link types used to build a
computer network?
a. Cablesb. Leased Lines
c. Last-Mile Links
d. Wireless Links
41. What are the categories of Transmission media?
a. Guided Mediai. Twisted - Pair cable
1. Shielded TP
2. Unshielded TP
ii. Coaxial Cable
iii. Fiber-optic cable
b. Unguided Media
i. Terrestrial microwave
ii. Satellite Communication
42. What are the types of errors?
a. Single-Bit errorIn a single-bit error, only one bit in the data unit has changed
b. Burst Error
A Burst error means that two or more bits in the data have changed.
43. What is Error Detection? What are its methods?
Data can be corrupted during transmission. For reliable communication errors
must be deducted and Corrected. Error Detection uses the concept of redundancy,
which means adding extra bits for detecting errors at the destination. The
common Error Detection methods are a. Vertical Redundancy Check (VRC)
b. Longitudinal Redundancy Check (VRC)
c. Cyclic Redundancy Check (VRC)
d. Checksum
44. What is Redundancy?
The concept of including extra information in the transmission solely for
the purpose of comparison. This technique is called redundancy.
45. What is VRC?
It is the most common and least expensive mechanism for Error Detection. In
VRC, a parity bit is added to every data unit so that the total number of 1s
becomes even for even parity. It can detect all single-bit errors. It can
detect burst errors only if the total number of errors in each data unit is
odd.
46. What is LRC?
In LRC, a block of bits is divided into rows and a redundant row of bits is
added to the whole block. It can detect burst errors. If two bits in one data
unit are damaged and bits in exactly the same positions in another data unit
are also damaged, the LRC checker will not detect an error. In LRC a redundant
data unit follows n data units.
47. What is CRC?
CRC, is the most powerful of the redundancy checking techniques, is based on
binary division.
48. What is Checksum?
Checksum is used by the higher layer protocols (TCP/IP) for error detection
9. List the steps involved in creating the checksum.
a. Divide the data into sectionsb. Add the sections together using 1's complement arithmetic
c. Take the complement of the final sum, this is the checksum.
50. What are the Data link protocols?
Data link protocols are sets of specifications used to implement the data
link layer. The categories of Data Link protocols are 1. Asynchronous Protocols2. Synchronous Protocols
a. Character Oriented Protocols
b. Bit Oriented protocols
51. Compare Error Detection and Error Correction:
The correction of errors is more difficult than the detection. In error
detection, checks only any error has occurred. In error correction, the exact
number of bits that are corrupted and location in the message are known. The
number of the errors and the size of the message are important factors.
52. What is Forward Error Correction?
Forward error correction is the process in which the receiver tries to guess
the message by using redundant bits.
53. Define Retransmission?
Retransmission is a technique in which the receiver detects the occurrence
of an error and asks the sender to resend the message. Resending is repeated
until a message arrives that the receiver believes is error-freed.
54. What are Data Words?
In block coding, we divide our message into blocks, each of k bits, called
datawords. The block coding process is one-to-one. The same dataword is always
encoded as the same codeword.
55. What are Code Words?
"r" redundant bits are added to each block to make the length n =
k + r. The resulting n-bit blocks are called codewords. 2n - 2k
codewords that are not used. These codewords are invalid or illegal.
56. What is a Linear Block Code?
A linear block code is a code in which the exclusive OR (addition modulo-2)
of two valid codewords creates another valid codeword.
57. What are Cyclic Codes?
Cyclic codes are special linear block codes with one extra property. In a
cyclic code, if a codeword is cyclically shifted (rotated), the result is
another codeword.
58. Define Encoder?
A device or program that uses predefined algorithms to encode, or compress
audio or video data for storage or transmission use. A circuit that is used to
convert between digital video and analog video.
59. Define Decoder?
A device or program that translates encoded data into its original format
(e.g. it decodes the data). The term is often used in reference to MPEG-2 video
and sound data, which must be decoded before it is output.
60. What is Framing?
Framing in the data link layer separates a message from one source to a
destination, or from other messages to other destinations, by adding a sender
address and a destination address. The destination address defines where the
packet has to go and the sender address helps the recipient acknowledge the
receipt.
What is Fixed Size Framing?
In fixed-size framing, there is no need for defining the boundaries of the
frames. The size itself can be used as a delimiter.
62. Define Character Stuffing?
In byte stuffing (or character stuffing), a special byte is added to the
data section of the frame when there is a character with the same pattern as
the flag. The data section is stuffed with an extra byte. This byte is usually
called the escape character (ESC), which has a predefined bit pattern. Whenever
the receiver encounters the ESC character, it removes it from the data section
and treats the next character as data, not a delimiting flag.
63. What is Bit Stuffing?
Bit stuffing is the process of adding one extra 0 whenever five consecutive
Is follow a 0 in the data, so that the receiver does not mistake the pattern
0111110 for a flag.
64. What is Flow Control?
Flow control refers to a set of procedures used to restrict the amount of
data that the sender can send before waiting for acknowledgment.
65. What is Error Control ?
Error control is both error detection and error correction. It allows the
receiver to inform the sender of any frames lost or damaged in transmission and
coordinates the retransmission of those frames by the sender. In the data link
layer, the term error control refers primarily to methods of error detection
and retransmission.
66. What Automatic Repeat Request (ARQ)?
Error control is both error detection and error correction. It allows the
receiver to inform the sender of any frames lost or damaged in transmission and
coordinates the retransmission of those frames by the sender. In the data link
layer, the term error control refers primarily to methods of error detection
and retransmission. Error control in the data link layer is often implemented
simply: Any time an error is detected in an exchange, specified frames are
retransmitted. This process is called automatic repeat request (ARQ).
67. What is Stop-and-Wait Protocol?
In Stop and wait protocol, sender sends one frame, waits until it receives
confirmation from the receiver (okay to go ahead), and then sends the next
frame.
68. What is Stop-and-Wait Automatic Repeat Request?
Error correction in Stop-and-Wait ARQ is done by keeping a copy of the sent
frame and retransmitting of the frame when the timer expires.
69. What is usage of Sequence Number in Relaible Transmission?
The protocol specifies that frames need to be numbered. This is done by
using sequence numbers. A field is added to the data frame to hold the sequence
number of that frame. Since we want to minimize the frame size, the smallest
range that provides unambiguous communication. The sequence numbers can wrap
around.
70. What is Pipelining ?
In networking and in other areas, a task is often begun before the previous
task has ended. This is known as pipelining.
71. What is Sliding Window?
The sliding window is an abstract concept that defines the range of sequence
numbers that is the concern of the sender and receiver. In other words, he
sender and receiver need to deal with only part of the possible sequence
numbers.
72. What is Piggy Backing?
A technique called piggybacking is used to improve the efficiency of the
bidirectional protocols. When a frame is carrying data from A to B, it can also
carry control information about arrived (or lost) frames from B; when a frame
is carrying data from B to A, it can also carry control information about the
arrived (or lost) frames from
3. What are the two types of transmission technology
available?
(i) Broadcast and (ii) point-to-point
74. What is subnet?
A generic term for section of a large networks usually separated by a bridge
or router.
75. Difference between the communication and
transmission.
Transmission is a physical movement of information and concern issues like
bit polarity, synchronisation, clock etc.Communication means the meaning full exchange of information between two communication media.
76. What are the possible ways of data exchange?
(i) Simplex (ii) Half-duplex (iii) Full-duplex.
77. What is SAP?
Series of interface points that allow other computers to communicate with
the other layers of network protocol stack.
78. 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".
79. What is frame relay, in which layer it comes?
Frame relay is a packet switching technology. It will operate in the data
link layer.
80. What is terminal emulation, in which layer it comes?
Telnet is also called as terminal emulation. It belongs to application
layer.
81. 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.
82. What is redirector?
Redirector is software that intercepts file or prints I/O requests and
translates them into network requests. This comes under presentation layer.
83. What is 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.
84. What is RAID?
A method for providing fault tolerance by using multiple hard disk drives.
85. What is 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.
86. What is Brouter?
Hybrid devices that combine the features of both bridges and routers.
87. What is cladding?
A layer of a glass surrounding the center fiber of glass inside a
fiber-optic cable.
88. What is point-to-point protocol?
A communications protocol used to connect computers to remote networking
services including Internet service providers.
89. 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.
90. What is attenuation?
The degeneration of a signal over distance on a network cable is called
attenuation
91. 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.
92.
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.
baud rate = (bit rate / N)
where N is no-of-bits represented by each signal shift.
93. 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.
94. What
are the types of Transmission media?
Signals
are usually transmitted over some transmission media that are broadly
classified in to two categories.
a.) 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.
b.) 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.
95. What
is Project 802?
It is a
project started by IEEE to set standards to 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.
96. What
is 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).
97. 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.
98. 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.
99. 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.
100. 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.
101. 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.
102. 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
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
103. 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 offer 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.
104. What
are major types of networks and explain?
- Server-based network: provide centralized control of network resources and rely on server computers to provide security and network administration
- Peer-to-peer network: computers can act as both servers sharing resources and as clients using the resources.
105. 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.
106. What
is mesh network?
A network
in which there are multiple network links between computers to provide multiple
paths for data to travel.
107. What
is 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.
108.
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.
109. What MAU?
In token Ring , hub is called Multistation Access Unit(MAU).
110. What is 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.
111. Why should you care about the OSI Reference Model?
It provides a framework for discussing network operations and design.
112. What is 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.
113. What is 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.
114. What is 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.
115. What is 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.
116. What is 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.
117. What is multicast routing?
Sending a message to a group is called multicasting, and its routing
algorithm is called multicast routing.
118. What is region?
When hierarchical routing is used, the routers are divided into what we will
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.
119. What is 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.
120. 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.
121. Expand IDEA.
IDEA stands for International Data Encryption Algorithm.
122. What is wide-mouth frog?
Wide-mouth frog is the simplest known key distribution center (KDC)
authentication protocol.
123. What is Mail Gateway?
It is a system that performs a protocol translation between different
electronic mail delivery protocols.
124. What is IGP (Interior Gateway Protocol)?
It is any routing protocol used within an autonomous system.
125. What is 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.
126. What is autonomous system?
It is a collection of routers under the control of a single administrative
authority and that uses a common Interior Gateway Protocol.
27. What is 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).
128. What is Gateway-to-Gateway protocol?
It is a protocol formerly used to exchange routing information between
Internet core routers.
129. What is 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.
130. What is 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.
131. What is 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.
132. What is 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.
133. What is 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.
134. What is SLIP (Serial Line Interface Protocol)?
It is a very simple protocol used for transmission of IP datagrams across a
serial line.
135. What is RIP (Routing Information Protocol)?
It is a simple protocol used to exchange information between the routers.
136. What is source route?
It is a sequence of IP addresses identifying the route a datagram must
follow. A source route may optionally be included in an IP datagram header
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