Networking Interview Questions & Answers

Posted On:January 1, 2019, Posted By: Latest Interview Questions, Views: 232, Rating :

Best Networking Interview Questions and Answers

Dear Readers, Welcome to Networking Interview Questions have been designed specially to get you acquainted with the nature of questions you may encounter during your Job interview for the subject of Networking. These Networking Questions are very important for campus placement test and job interviews. As per my experience good interviewers hardly plan to ask any particular questions during your Job interview and these model questions are asked in the online technical test and interview of many Medical Industry.

1. What is OSI model and how is it important in networking?

The OSI model is the one which divides the network communication as consisting of 7 different layers. These include all the layers between the lower-most physical layer and the higher level Application layer ( Datalink, Network, Transport, Session and presentation layers). What it does by categorizing so is to just distinguish the various functionalities that the protocols may offer over a network transmission. Some of the soecific protocols just try to concentrate the details till the layer necessary, thereby making it simpler for the co-existence of different protocols and different standards.

Interview Questions on Networking

2. What are the layers that are present in the DOD and the TCP/IP models?

The TCP/IP networking model consists of the Application, transport, network, datalink and physical layers. The DOD model has the application, host-to-host, internet, network access layers – 4 in total.


3. What is the type of cable used for connecting similar devices?

The similar devices are usually connected using the cross wired cables. This  reduces the noise and enable smooth communication. 1,2 pins of the cross wire and meant for sending and 3,6 points are for reception of data.


4. What are the advantages of twister pair cables?

The twisted pair has two independent wires insulated with plastic coating and interwoven with each other. This type of insulation prevents cross talk and avoids the undesirable induction effects from magnetic fields which may generate losses and corruptions. These can be used to carry signal over reasonable distances.


5. Briefly describe the RIP.

The Routing Information Protocol is one that is used to give the routing information along with the data that is being sent. This has become obsolete with emergence of large networks and the internet. However, in the local internal networks with fixed number of hop spots, the RIP can serve as an efficient way to transfer data from one point to another. The router need not do much of work in identifying the shortest route etc.


6. How does ARP differ from RARP?

The ARP (Address Resolution Protocol) is meant for the identification of a remote system’s physical address, when the host knows only its network address. The Reverse ARP (RARP) is used when the host wants to know its own network address when all it has is the physical address of itself.


7. What is the difference between the TCP and UDP protocols? When are they used?

The TCP is a connection oriented protocol while the UDP is not. This means that the TCP based communication is more reliable than the UDP. The sequence of acknowledgements that are associated with TCP makes it more effective for transmission of control information and other important commands. The UDP on the other hand makes it possible to have a quick transmission of data across the various systems in the network. This is used when a few packet losses are not a matter of concern (like in Live video streaming).


8. How is bit rate different from baud rate of a network?

The bit rate represents the number of bits that are transferred in one second. But the baud rate refers to the number of signals at the hardware level that are transmitted in one second. The baud rate is thus obtained by dividing the bit rate by the N (number of signal units per bit).


9. What is Remote Procedure Call (RPC)?

RPC refers to the mechanism of invoking a function that is implemented in a remote system through the network. The RPCs can be performed using many different protocols and standards. The usual standards are based on the XML based data that is being transferred across the TCP protocol from one system to another.


10. What is a subnet? What is a subnet mask?

The subnet refers to the dividing of a network based on the network addresses that are assigned. This way the security of the networks are established according to the different sub-networks and the huge network can be made easily manageable based on the divisions. The subnet mask refers to the number which identifies the significant values in the address of the systems. For example a mask of establishes the fact that the sub-network is having only 255 systems that are distinguished by the last part of the IPV4 address.


11. What is a FTP?

The File Transfer Protocol is one that is designed to enable quick transfer of files from one system to another. The file servers that are deployed have the ports listening for incoming FTP requests. The requests for specific files from clients are then responded with the link to the file that they request.


12. What are transaction server?

Transaction server refers to the server with a database engine to which the other systems send remote procedure calls. These calls in turn will be signalling a batch execution of the SQL statement from the database. The SQL queries succeed or fail as a batch. The entire message transfer between the transaction server and a client is in the single request/reply model.


13. What is horizontal and vertical scaling?

The horizontal scaling refers to the expansion of the client or workstation base in a server/client based network. This may indicate increase in number of clients or increase of client dependency on the server – meaning a additional load on the servers.  The vertical scaling on the other hand refers to server expansion in number or performance power.


14. What are sockets and ports? How many ports are available on a normal system?

Sockets represent the end points of communication. Assuming a channel of communication established between two systems, the endpoint in which each system received or sends data is referred to as sockets. Ports refer to the outlets through which the system can be connected with others. The number of ports in a normal operating system is 65536. The first 1024 ports are allocated for general usage and system functionalities.


15. What is two-tier architecture?

A 2-tier architecture refers to the server-client model of networking. Here the applications are entirely residing on the server side with minimal operations on the client side. Most of the time it is just the user interface that lies in the client side and all the computations are carried out in the server side of the application. Database server and print server are typical examples of such an architecture.


16. What is a general middleware?

The general middleware is one that is lying below the UI application and this consists of all the communicative procedures like RPCs, authentication procedures, network/OS extensions with queuing services etc. This is a platform below which a complex storage mechanism or any complex logic is implemented and over which the development of different access mechanisms takes place.


17. What is meant by beaconing?

This is the mechanism of auto-repair in the networks like the ring and FDDI. The network hotspots can detect any misled transmission or malfunctions in the network. This can again be used within the network to make it repair the condition by itself.


18. What is the difference between NETBIOS and NETBEUI?

The NETBIOS is the abstracting layer of software there hides the hardware specifics of the network from the applications. The NETBEUI refers to the user interface (NETBIOS extended User Interface) that gives access to the NETBIOS functions like sending and receiving messages through the network interface.


19. What is the difference between the hub and switch?

The hub is just a junction where the systems are integrated but there is no logically divided network. Any packet received through a hub is sent across to all the other members connected to the hub (which is then resolved using Collision detection mechanisms). It can have a max speed of 10mbps. The switch creates a logically divided network with all the systems having a logical network address for each system and the max speed achievable is 100mpbs.


20. What is network cluster?

The cluster is the network logic that combines the resources and processing powers of many systems and identifies it as a single entity. Distributed systems and Network of Workstations come under such kind. The cluster usually has a merged network identity within which there can be individually separate systems with their own identity.


21. What is attenuation? How is it overcome?

The attenuation refers to the degradation of signal strength when it is transmitted for a long distance over cables. This is overcome be placing repeaters at specific distances.


22. What are the different types of transparencies that NOW middleware provides you?

The different types of transparencies include namespace, failure, administration, distributed time, location , logon, access transparencies.


23. What is DHCP?

The DHCP stands for Dynamic Host Configuration Protocol which is responsible for identifying the unused network addresses from the particular hotspot and assigning it to the specific system. This applies to the IP networks of computers where many intermediate routers.


24. What is an Object server?



25. What is a Transaction server? 

With a transaction server, the client invokes remote procedures that reside on the server with an SQL database engine. These remote procedures on the server execute a group of SQL statements. The network exchange consists of a single request/reply message. The SQL statements either all succeed or fail as a unit.


26. What is a Database Server? 



27. What are the most typical functional units of the Client/Server applications? 

User interface

Business Logic and 

Shared data.


28. What are all the Extended services provided by the OS?

Ubiquitous communications 

Network OS extension

Binary large objects (BLOBs)

Global directories and Network yellow pages

Authentication and Authorization services

System management

Network time

Database and transaction services

Internet services

Object- oriented services


29. What are Triggers and Rules? 

Triggers are special user defined actions usually in the form of stored procedures, that are automatically invoked by the server based on data related events. It can perform complex actions and can use the full power of procedural languages. 

A rule is a special type of trigger that is used to perform simple checks on data.


30. What is meant by Transparency? 



31. What are TP-Lite and TP-Heavy Monitors? 

TP-Lite is simply the integration of TP Monitor functions in the database engines. TP-Heavy are TP Monitors which supports the Client/Server architecture and allow PC to initiate some very complex multiserver transaction from the desktop.


32. What are the two types of OLTP? 

TP lite, based on stored procedures. TP heavy, based on the TP monitors.


33. What is a Web server? 

This new model of Client/Server consists of thin, protable, "universal" clients that talk to superfat servers. In the simplet form, a web server returns documents when clients ask for them by name. The clients and server communicate using an RPC-like protocol called HTTP.


34. What are Super servers? 



35. What is a TP Monitor? 



36. TP Monitor does mainly two things extremely well. They are Process management and Transaction management.? 



37. What is meant by Asymmetrical protocols?



38. What are the types of Transparencies? 

The types of transparencies the NOS middleware is expected to provide are:-

Location transparency

Namespace transparency

Logon transparency

Replication transparency

Local/Remote access transparency

Distributed time transparency

Failure transparency and

Administration transparency.


39. What is the difference between trigger and rule? 

The triggers are called implicitly by database generated events, while stored procedures are called explicitly by client applications.


40. What are called Transactions? 

The grouped SQL statements are called Transactions (or) A transaction is a collection of actions embused with ACID properties.


41. What are the building blocks of Client/Server? 

The client

The server and



42. Explain the building blocks of Client/Server? 

The client side building block runs the client side of the application.

The server side building block runs the server side of the application.


43. What are all the Base services provided by the OS? 

Task preemption

Task priority


Interprocess communications (IPC)

Local/Remote Interprocess communication


Intertask protection


High performance file system

Efficient memory management and

Dynamically linked Run-time extensions.


44. What are the roles of SQL? 

SQL is an interactive query language for ad hoc database queries.

SQL is a database programming language.

SQL is a data definition and data administration language.

SQL is the language of networked database servers

SQL helps protect the data in a multi-user networked environment.

Because of these multifacted roles it plays, physicists might call SQL as "The grand unified theory of database".


45. What are the characteristics of Client/Server? 


Shared resources

Asymmentrical protocols

Transparency of location


Message based exchanges

Encapsulation of services



Client/Server computing is the ultimate "Open platform". It gives the freedom to mix-and-match components of almost any level. Clients and servers are loosely coupled systems that interact through a message-passing mechanism. 


46. What is Structured Query Langauge (SQL)?

SQL is a powerful set-oriented language which was developed by IBM research for the databases that adhere to the relational model. It consists of a short list of powerful, yet highly flexible, commands that can be used to manipulate information collected in tables. Through SQL, we can manipulate and control sets of records at a time.


47. What is Remote Procedure Call (RPC)? 




48. What are the main components of Transaction-based Systems? 

Resource Manager

Transaction Manager and

Application Program.


49. What are the three types of SQL database server architecture? 

Process-per-client Architecture. (Example: Oracle 6, Informix )

Multithreaded Architecture. (Example: Sybase, SQL server)

Hybrid Architecture


50. What are the Classification of clients? 

Non-GUI clients - Two types are:-

Non-GUI clients that do not need multi-tasking

(Example: Automatic Teller Machines (ATM), Cell phone)

Non-GUI clients that need multi-tasking

(Example: ROBOTs)


GUI clients

OOUI clients


51. What are called Non-GUI clients, GUI Clients and OOUI Clients? 

Non-GUI Client: These are applications, generate server requests with a minimal amount of human interaction.

GUI Clients: These are applicatoins, where occassional requests to the server result from a human interacting with a GUI

(Example: Windows 3.x, NT 3.5)

OOUI clients : These are applications, which are highly-iconic, object-oriented user interface that provides seamless access to information in very visual formats.

(Example: MAC OS, Windows 95, NT 4.0)


52. What is Message Oriented Middleware (MOM)? 

MOM allows general purpose messages to be exchanged in a Client/Server system using message queues. Applications communicate over networks by simply putting messages in the queues and getting messages from queues. It typically provides a very simple high level APIs to its services. 

MOM's messaging and queuing allow clients and servers to communicate across a network without being linked by a private, dedicated, logical connection. The clients and server can run at different times. It is a post-office like metaphor.


53. 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.


54. 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.


55. 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.


56. 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. 


57. 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.


58. 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.


59. What is OLTP? 




60. What is meant by 3-Tier architecture? 


Example: TP monitor, Web.


61. 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.


62. What is Load balancing? 



63. What are called Fat clients and Fat servers? 




64. What is meant by Horizontal scaling and Vertical scaling? 



65. 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.


66. What are the two broad classes of middleware? 

General middleware

Service-specific middleware.


67. What are the types of Servers? 

File servers

Database servers Transaction servers Groupware servers Object servers Web servers. 


68. What is a File server? 



69. What are the five major technologies that can be used to create Client/Server applications? 

Database Servers

TP Monitors


Distributed Objects



70. What is Client/Server?



71. 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.


72. 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 service.


73. What is ACID property? 

ACID is a term coined by Andrew Reuter in 1983, which stands for Atomicity, Consistence, Isolation and Durability.


74. What are Stored procedures? 

A stored procedure i s named collection of SQL statements and procedural logic that is compiled, verified and stored in a server database. It is typically treated like any other database object. Stored procedures accept input parameters so that a single procedure can be used over the network by multiple clients using different input data. A single remote message triggers the execution of a collection of stored SQL statements. The results is a reduction of network traffic and better performance.


75. What is wide-mouth frog? 



76. What is passive topology? 


Example for passive topology - linear bus.


77. What is region? 



78. What is virtual channel? 



79. Difference between the communication and transmission? 




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




81. What are the advantages and disadvantages of the three types of routing tables? 



82. What is Beaconing? 



83. What does the Mount protocol do ?



84. What are Digrams and Trigrams? 



85. What is the HELLO protocol used for? 



86. 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 the PAD and the network, called X.29. Together, these three recommendations are often called "triple X".


87. What is attenuation? 



88. What is Protocol Data Unit? 



89. Name the port used by PING.

Always remember that PING does not use any port. As PING is based upon layer 3 protocol, it never uses any computer port. A simple variation of the question could be: Does PING use UDP? Or Does PING use TCP? Again remember that UDP and TCP are layer 4 protocols and PING has nothing to do with them.





91. What is difference between ARP and RARP? 




92. What is MAC address? 



93. What is terminal emulation, in which layer it comes? 



94. 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:


Unguided Media:




95. What are major types of networks and explain?

Server-based network.

Peer-to-peer network.





96. What is multicast routing? 



97. What is the difference between routable and non- routable protocols? 



98. What are the different type of networking / internetworking devices? 








99. What is logical link control? 



100. What is traffic shaping? 



101. What is NETBIOS and NETBEUI? 




102. Why should you care about the OSI Reference Model? 

It provides a framework for discussing network operations and design. 


103. What is Proxy ARP?



104. What is EGP (Exterior Gateway Protocol)? 



105. What is Kerberos? 



106. What is Mail Gateway? 



107. What is RIP (Routing Information Protocol)? 



108. What is NVT (Network Virtual Terminal)? 



109. What is source route? 



110. What is BGP (Border Gateway Protocol)? 
