OSI Reference Model and TCP/IP Model Interview Questions and Answers

OSI Reference Model and TCP/IP Model Interview Questions and Answers

Most of the IT farm's job interview or written exam has at least one question regarding OSI or TCP/IP model. Some questions of this topic are presented here with very concise answers. All these questions are very helpful for the interviewee. Posts like "IT Executive", "Network Engineer", "Junior System Engineer" etc. have such type of questions in the job selection written exam. These questions will also helpful for strengthening basic knowledge of OSI model also.

Page Font Styles

  • Question and Answers are arranged sequentially.
  • "BOLD Font" indicates Question.
  • "Normal Font" indicates Answer.

What is "Segment"?

"Segment" is a PDU (Protocol Data Unit) of Transport layer of OSI model.

What is the PDU of "Network layer" and "Data link layer".

PDU for Network Layer is: "Packet" and PDU for Data Link Layer is :"Frame"

You have one IP: In which layere this IP works?

Network layer.

You are in home. But you need to access the office server router. How can you do that?

By using "Telnet"

DNS uses which protocol? Why?

DNS uses both TCP or UDP or both. UDP can handle only 512bytes. If data size is withing 512 bytes UDP is used, otherwise, TCP is used.

Which layer is closer to the user?

Upper layer i.e. Application layer is closer to the user.

Differentiate between forward lookup and reverse lookup in DNS?

  • Forward lookup is: name-to-address,
  • Reverse lookup is: address-to-name.

what are the difference between TCP and UDP?

  • TCP: Connection oriented protocol, acknowledged one, Point to point communication.
  • UDP: Connection less protocol, unreliable, less traffic

What is IPSec?

IPSec is "Internet Protocol Security". It is a suite of protocols for securing Internet Protocol(IP) communications.

What is the way to establish a TCP connection?

By using acknowledgement.

What is the difference between flow control and error control?

  • Flow control: adjust and confirm data flow rate for successful transmission.
  • Error Control: a way to recover corrupted data .

Mark one of the most important difference between TCP and UDP.

TCP is a connection-oriented and UDP is a connection-less protocol

Mention one real place to use TCP/IP.

LAN cards

What is the responsibilities of Network Layer?

  • Logical addressing
  • Best effort delivery

Data link layer is sub-divide into how many groups?

  • 2 sub-divided groups: MAC Layer and LLC layer
  • MAC: Media Access Control/Medium Access Control
  • LLC: Logical Link Control

What is the port number of Telnet and DNS?

Telnet = 23 and DNS = 53

What is the port number of ftp(data) and ftp?

ftp(data) = 20 and ftp=21

ARP resolves what? Address or IP?

ARP stands for Address Resolution Protocol. It helps to find the hardware address or MAC address when IP address is known.

Which layer of OSI is responsible for end-to-end communication?

Transport layer.

Why we have to use router?

To communicate several networks, routers are used. Routers have both broadcast domain and collision domain.

RARP resolves what? Address or IP?

RARP stands for Reverse Address Resolution Protocol. It helps to find the IP address when physical or hardware or MAC address is known.

What is OSI model?

OSI model is a reference model containing 7 layers such as physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer.

What is TCP/IP model?

TCP/IP model is an implementation of OSI reference model. It has five layers. They are: Network layer, Internet layer, Transport layer and Application layer.

What is the full form of OSI and TCP/IP model?

  • OSI stands for = Open Systems Interconnection (OSI) model
  • TCP/IP stands for = Transmission Control Protocol/ Internet Protocol

What are the differences between OSI and TCP/IP model?

Important differences are:

OSI is a reference model and TCP/IP is an implementation of OSI model.

OSI has 7 layers whereas TCP/IP has only 4 layers The upper 3 layers of the OSI model is combined on the TCP/IP model.

OSI has: physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer TCP/IP has : Network layer, Internet layer, transport layer and application layer.

What are the differences among router, switch, bridge and hub?

All of them are devices and are used in network. Their differences are:

  • Router: Layer 3 device, can work on physical, data and network layer.
  • Switch: Layer 2 device, can work on data link layer
  • Bridge: Layer 2 device, can work on data link layer.
  • Hub: Layer 1device, just a multi-port repeater and works on physical layer

Switch operates on which layer of OSI model?

Normal switch operates at Layer 2 i.e. data link layer and Intelligent switch operates at Layer 3 i.e. network layer.

What is the upper layer name of OSI layer?

Application layer.

Name 4 example of application layer?

DNS, FTP, Telnet, http

How does ARP response the request?

ARP sents the request in broadcast, response is unicast

Error control is down in which layer?

Layer 4

Name the 2 sublayers of data link layer.

MAC sublayer and LLC sublayer

How is data send by IP layer?

IP layer PDU is "packet". So, data is send as packet.

TCP/IP has how many layers?

5 layers: Network layer, Internet layer, Transport layer and Application layer.

What is the data unit of "Transport layer"?


What are the differences of MAC sublayer and LLC sublayer?

In fact, Data Link layer has 2 sublayes: MAC sublayer & LLC sublayer.

  • MAC sublayer(802.3): defines how to transmit data on physical layer
  • LLC sublayer(802.2): responsible for identifying different protocol logically & encapsulate them.

If you enjoyed this post, please consider to leave a comment at the end of the page or subscribe to the feed and get future articles delivered to your feed reader.

© rancidTaste

More by this Author

Comments 218 comments

ravisankar 7 years ago

It is very useful tome.

Thank u for providing this site.

it is easiely question 7 years ago


navneet 7 years ago

very much helpful for interviews

Hassan Azmat 7 years ago


Very useful information has been mentioned above....

Thank you so much i have always seeking these kinds of posts.....

thanks again

Arghya Chatterjee 7 years ago

Very useful questions .Thanks

Tapan Kumar Kundu 7 years ago

It's Very useful site.

suniel 7 years ago

Awesome post, you are too good,keep posting ,,

Thanks a lot

r41 7 years ago

It was much useful ..thanks

Rejath 7 years ago

Awesome post, you are too good and superb!!!!!!!!!!!!!!!!!!!!!!!!!!!!!,keep posting............etc

Thailungpou Gonmei 7 years ago

very very nice and Thanks you so much and appreciate your awnsome post,

Karim Hunzai 6 years ago


short and to the point but very useful

bhupal 6 years ago

thanks...its so cool

Raj 6 years ago

Fabulous :-) Very useful information good for preparing interviews easily we can get thru...

Many Thanks !!!!!!!!!! Gr8

Syed Yasir 6 years ago

Ut Was Really Realy usefull and informative Thanks.

It Could be more better with little detaild answers

priyank pratik 6 years ago

great for quick revision

sriram 6 years ago

thnk u so much for giving guidence . i love u

sriram 6 years ago

thnk u so much for giving guidence . i love u

Sam 6 years ago

It was really so useful.. Thanks a lot

Bharath 6 years ago

Thanks for your effort in posting answers for all these questions...

skumar 6 years ago

very usefull for my class. thank you. you saved my day.

Jsaison 6 years ago

Very good article..

RITU  6 years ago


Manish 6 years ago

Good one for those who need such basic things.

vasnt naik 6 years ago

This guidanc are verry use full in net work fondament

vasant naik 6 years ago

its verry usefull topic for n+

Girish 6 years ago

Very Sort but Useful, should have some pictorial answer.


madhu 6 years ago

Its really a nice stuff.... one more request and suggestion s please give some more info in each layer ,its fun's,protocols used etc... so that it would help some more ppl like me to gain knowledge as wel easy prep to placements

CHETAN 6 years ago

THANKS A LOT BRO !!!!!!!!!!!!!!

sailesh 6 years ago

Very useful stuff to all network people

Thanks For the post

kuldeep 6 years ago

nice i enjoyed ,.........

prashant 6 years ago


satish chandra 6 years ago


satish chandra.

cate.tee 6 years ago

nice i enjoyed. ......thanks very much,....

Wannafly 6 years ago

great sharing dude..

tinerbell 6 years ago

very gud.

Rajesh Acharya 6 years ago

This site is very useful for all about osi and tcp/ip

raghu 6 years ago

this is cery good to learn.

Ahmad 6 years ago

its really good when ur interview call on next day :)

manish yadav 6 years ago

it very helpful for unknown stunent which want to anything about osi or networking

Goodluck Gunda 6 years ago

Its a very good for revision. Thanks for the site

Puneet Kumar 6 years ago

Awesome information.


Quili 6 years ago

Good info, nice to read so update more questions????

jovijo 6 years ago

this is sum great stuff enjoying it too much :life saver

kingsG 6 years ago

thanks for this wonderful idea

6 years ago

it sucked. no correct answers . all were way off. don't touch me

vikas jain 6 years ago

its really gud,

final touch..

Veerendra Patil 6 years ago

it's gud stuff and very useful

SANjay 6 years ago

Really very user full for any Interview

Shaik 6 years ago

Very good compilation of basic nw info on OSI and TCP/IP layers. Only thing is there is a wrong info repeatedly on no. of layers of TCP/IP given as 5 instead of 4. Hope It will be rectified soon. Great work keep it up.

marving 6 years ago

this website is very useful. thanks

satyendra kumar 6 years ago

Thanks dear, this is very useful

Ranjit 6 years ago

This Web link is very useful .......... Thanks

rannjit 6 years ago

really good stuff for revising

Puneet Kwatra 6 years ago

Good one for revision.

Rahul Kumar 6 years ago

Really At the time of interview its helpful

Sudhir Arya 6 years ago

Really it very good site to get some important knowledge

kailas 6 years ago

Really it very good site to get some important knowledge

6 years ago

thank you... this page is very useful.

Shyam 6 years ago

It is very useful to know the basic fundamental of Network, Data Link and Physical Layer of OSI model.

Niraj 6 years ago

Thanks.. today only in my classroom, Teacher was teching LLC/MAC in Datalink layer but did not get it..

Here in 1 line its explained properly.. and additionally I got some other useful questions..

Jiten 6 years ago

Thanks a lot to provide variety of information abt layers!!

astric 6 years ago

tahnx for providing this discussion...

Ernest M 6 years ago

The best and most precise piece of revision summary ever.

vivian 6 years ago

very helpful

Anky 6 years ago

Thanks it was much helpful and knowledgable.

vinod singh negi 6 years ago

Thanks for this information

it is basic knowledge of networking for me

thanks again...........

Heena 6 years ago

Certainly useful..very nice article..thnx..

shashidhaar 6 years ago


shashidhar vakwady 6 years ago

Certainly useful

Avez 6 years ago

Really very nice man

pinky 6 years ago

Usefull revision.. thanks

prashant  6 years ago


pradip kar 6 years ago

It is indeed very informative.Please update me more on any topic .


Saki 6 years ago

It's really great!

rohit sharma (bhopal) 6 years ago

these information will be really usefull for a fresher.thans alot keep posting

Nishant Jain 6 years ago

Respected sir,

Extreemly thank u sir for these question

you'r question realy to good and very useful in quiz, exame, etc, and sir plz update more these type question it's my request.

Thank's for u'r kindness.

santosh 6 years ago


khalid 6 years ago

it is best website for networking questions

poorani 6 years ago

thanks ... it s very helpful for me

Ankit  5 years ago

thanks very useful..keep posting like this..gr8 help

Raj 5 years ago

Thanks for the nice information .... indeed helpful ... hurrayy!!!!!!!!!!!!

Venu 5 years ago

Thanks for quick quiz

IRAM 5 years ago

Very helpul and important information................Thanx alot

karthik 5 years ago

gud work...cheers mate

RANITA 5 years ago


vijay dewra 5 years ago


keep it on

thanks a lot

rabia 5 years ago


mitu sharma 5 years ago

Thanks, its really helped me a lot.

matter is reliable and relevant

Taurai 5 years ago

I thank you with this usefull information pliz send more raleted with network

Pushpa.R 5 years ago

Thank u,

This site is very use full to me.

m.shobbana 5 years ago

it's very useful to me.plz send more questions.

Anant  5 years ago

It very gooood man

niyaz(Saharsa) 5 years ago

Respected sir,

Extreemly thank u sir for these question

you'r question realy to good and very useful in quiz, exame, etc, and sir plz update more these type question it's my request.

Thank's for u'r kindness

waqas 5 years ago


kisan 5 years ago

very great job. informations are really helpful. awesome

viresh ray 5 years ago


Jyoti  5 years ago

it was knowledgable and nice....!!!!

aini 5 years ago

very helpful site...it helps me alot..

Nirmit 5 years ago

very good questionnaire, helped a lot to refresh the concepts.

deepanshi 5 years ago

gr8 help....thnxxxx

saheeba 5 years ago

thanks a lot! very helpful questionnaire!:)

G.R.SELVAKUMAR 5 years ago

Thanks a lot. Excellent questions and Answers. Very useful this one...

Sada 5 years ago

Very useful link......

saurabh pandey 5 years ago

thank you so much...!!

satyendra mishra 5 years ago

Very useful set o f quwstions

ranji 5 years ago

thank u... it is very usefull

Levi 5 years ago

thabks! very useful link

jewar 5 years ago

i am intedredsted if you you send me such like answer and quastion with my email

jyoti 5 years ago

thankyu very much..jus cleard basic knowldg abt n/wking..

Bakshu 5 years ago

it's more valuable information....!Thank u keep on providing..!

ruban 5 years ago

it helped me in interview i am so thankful to you. rubanchakky@gmail.com

Hamid 5 years ago

Weldone......Good Selection of Questions

narendra 5 years ago

This Article is very good

Thanks for the creator.

I Got good Knowledge by reading this.

AMOL 5 years ago


Vijay 5 years ago

This is really nice article which is very helpful for us .........thanks

Yogesh 5 years ago

It's very nice & usful for interview.,....

Thank you

anusha 5 years ago

very helpful. thanks a bunch!

tomas 5 years ago


abhijit 5 years ago

Grt ... very helpful.. thanks once again..

manoj sagar 5 years ago

there are so many good questions.... thanx 4 providing us.

shkhan 5 years ago

thanks. very useful knowledge about networks for interviews/exams. great. again thanks.

Sajeev 5 years ago

Awesome... Great questions. No beating around the bush, answers were simple and straight to the point. Thanks a million.

Riyaz 5 years ago

The answers in this link are so much beneficial!!!!!!!!!!!!!!!!!!!

yogesh 5 years ago

thanks nice qns easy to prepare.........

pushpa tewari 5 years ago

thanks tome its a great package of help

Rabindra jha 5 years ago

its so easy and more valuable for us thanks for it

Ashish 5 years ago

Thanks for providing such kind of knowledge

shimaa 5 years ago

it's very useful thanks alot

Yogi 5 years ago

Nice Collection Dude very informative....Hats up 2 U

sangeeta 5 years ago


tapan kumar barik 5 years ago

It is veery good page..............

i like it

Ada 5 years ago

Very useful simple Q&A for starters like me. Thank you so much!

ankit pagare 5 years ago

thanks, it is very usefull for me

Parshuram maddheshia 5 years ago

This is a usefull site

Parshuram maddheshia @ adarshmani 09838280104 5 years ago

This is a usefull site. We are love it

harmeet 5 years ago

good information

Thanks :)

senthilnathan 5 years ago

very useful

suwarna 5 years ago

its realy useful

sahil j 5 years ago

good short and accurate

Bhaarat 5 years ago

Thanks.. very nice answers

amit chadha 4 years ago

its really useful..thnks for this information.......

Amr 4 years ago


Deepak 4 years ago

Thanks a ton please provide some more questions and interesting games bsed on OSI

Raviraj Rajput CCIE 4 years ago

it is very useful

out tcp/ip layer only four

vikas singh 4 years ago

such a helpful for us.......

it's a great.....

keep it up dear friend................

rakesh 4 years ago

it really made a difference. thanks dude

shravan 4 years ago

excellent buddy

thanks for this information

Jitender Rana 4 years ago

Great very helpfull for new comers Thankyou.......

srinu 4 years ago

thank you very much

Mukesh choudhary 4 years ago


Vaishu 4 years ago


Its very helpful to Me.....

Shreeshail K K 4 years ago

its really useful..thnks for this information.... am realy happy all off q and ans

Vikas Soni 4 years ago

Really good and useful....Thanks!!!!!!!!

Rajesh 4 years ago

Truly useless info.. No one asks so silly question in an interview.. Grow up kid..

karthick 4 years ago

tanks ,,,use full questions

sreelal 4 years ago

thank u

Azib Naseem 4 years ago

Great work, it is very useful for me, keep it up....

tanvir hasan 4 years ago

great info...

Ravi shankar 4 years ago

Its very useful to face interview .so thank U

Goutham 4 years ago

Very useful and quick refresh... thanks !!

wasim akram 4 years ago

it is very usefull ..........thanks

Neelam 4 years ago

thank you so much its very helpful specially for me thanks

sumaira 4 years ago

it's really helpful JzakALLAH hoo khairan for this useful information.

arifa 4 years ago

what is the best usage of both models?

renugoyal 4 years ago


PM 4 years ago

These are good explanations to someone trying to clear up what these layers do. Not for an interview, but just for an understanding.

ahmed 4 years ago

thanks a lot

Latif 4 years ago

So easy

SANI 4 years ago


Vinod 4 years ago

yes.. i like it.............

THAMEEM 4 years ago

ITS INTERESTING.........................................

dsouza 4 years ago

very useful... thanks

siva 4 years ago

use ful questions for quick revision...

vipin kr.pandey 4 years ago

this notes very usefull for me ....

nnn this awesome .....


sowmya 4 years ago

Thank you

rasheed 4 years ago

super thank you but we need more keep posting

Ruth 4 years ago

Thanks alot for this article. Keep up the good works.

nouf 4 years ago

verymuch useful................. keep posting like this.....

Rohit verma 4 years ago

well done good questions...

kanchan 4 years ago

good collection of question .ITs very helpful for online test of reliance communication

G.D 4 years ago

very helpful and need to be up-dated

Anil 4 years ago

Very useful content.

balakrishna 4 years ago

Very Good collection

anil 4 years ago

thanks given interview types question and answer more

Pooja 4 years ago

superb, man

kiran 4 years ago

very help full this site thank you

Mahesh.J 4 years ago

good collection of questions man, keep doing, this may help to freshers those who are going to attend interviews..

Pradnya Patil 4 years ago

thanx you help full this site

pachai 4 years ago


tinu 4 years ago

thank you . it is very useful to go throuh the computer networks in a very efficiently within a short time .

rajesh kumar 4 years ago

many many thanks for these qs

sachin shivhare 4 years ago

Awesome...but TCI/IP Model is having only 4 Layers , here mentioned 5 instead of 4...Rest of Answers are good...;)

syali3112@gmail.com 4 years ago

it was very knowledgeable

shweta 4 years ago

its very helpfull questions....

Dhawan Shringi 4 years ago

Thanks, great collection :)

xyz 4 years ago


Ajit kumar 4 years ago

good question ,, but easy.. so ply maintain level of ccna...

Kervens 3 years ago

That's Very usefull thanks a lot

r.chary 3 years ago

excellent qstns

Monica 3 years ago

The questions r helpful for me..plz provide more questions with detailed answers..thank you

vira 3 years ago


Gopal Krishna Pandey 3 years ago

awesome and deep knowledge in TCP/IP thanks

Alsadig Bashir 3 years ago

This is excellent information , feed me more ...

clarence 3 years ago

ts good for making revevision

PANKAJ TIWARI 3 years ago


PANKAJ TIWARI 3 years ago

but one mistake in doc

chandan 3 years ago

This's very helpful for me ..thanks

Anand 3 years ago

Thanks a Lot...!!!

sandile 3 years ago

useful questions hey

Kuharita 2 years ago

Very informative and helps for interview prep

kavita rathore 2 years ago

very helpful for me for viva

kavita rathore 2 years ago

very helpful for me for viva

sreeha rojer 2 years ago

superbbb...thanks alot:-)

imran khan 2 years ago

very usefull, Thanx a ton


This link is much useful for me and for them as well who really like IT ..It was awesome ..Keep it up and post much more about all networking questions for any group ... Its really wonderful ..I will give you out of out ..Thanks once again ...

ajit 2 years ago

This link is really wonderful ...it's more useful

thanks a lot

Tarun 4 months ago

Very Useful


Vipin Antil 2 months ago

Please check Tcp/Ip model layer . It has 4 layer not 5 layer

    Sign in or sign up and post using a HubPages Network account.

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.

    Click to Rate This Article