Common Networking Interview Questions & Answers you must Know!!!
You might be thinking, What is networking? is it really so Important? why it is been Hyped up so much these days? Let me first make you understand that:
- If you are in a video conference, what you are experiencing in that platform is the resource sharing. Instead of sharing the resources with your folks physically, you are relying on the computers to do the same when you are in remote location. This is one form of Computer networking which you are using.
- If you are working in an organization and want to use a printer for getting the hard copies of your resource, you definitely need to share the printer with your peers. Since all the computers are connected to the printer locally (LAN) you need to access the common printer meant for all. This is another form of Computer Networking.
- Accessing your web and responding to the login forms in the same is also the form of computer networking.
So, the list goes on. As the web is growing faster and with the advent of latest connectivity standards like Wi-Fi 6 and so on, the computer networking is becoming an essential thing for everyone!!
and now i am sure, if you are reading this you might be gonna appear for its interview hence must tell you my friend that interview is not a test of your knowledge but your ability to use it at the right time. So, you can know everything but if you have not gone through relevant questions which you can expect on the interview, there are high chances that you might mess up your interview and no one really wants that, right? (Your Neighbors and relatives don’t count)
So before appearing in an interview on networking, I hope you would go through this list of most likely to appear questions which will surely increase your chances of clearing that interview. here i am giving you few most likely to ask questions but if you want to get a comprehensive idea of many more networking interview questions, you can check it out here
With that being said, lets now proceed with the networking interview questions!
What are layers in OSI model?
There are a total of 7 layers in OSI model with each layer having its own importance:
1. Physical Layer
2. Data Link Layer
3. Network Layer
4. Transport Layer
5. Session Layer
6. Presentation Layer
7. Application Layer
Explain in detail the main functions of each layer of OSI model.
1. Physical Layer
• It is the lowest layer in OSI reference model.
• It is used for the transmission of an unstructured raw bit stream over a physical medium.
• Here the data is transferred either in the form of electrical/optical or mechanical form.
• It is mainly used for the physical connection between the devices, and such physical connection can be made by using twisted-pair cable, fibre-optic or wireless transmission media.
2. Datalink Layer
• It is used for transferring the data from one node to another node.
• It receives the data from the network layer and converts the data into data frames and then attach the physical address to these frames which are sent to the physical layer.
• It enables the error-free transfer of data from one node to another node.
• Some functions of data link layer are: Frame synchronization, Flow control, Error control, Addressing, Link management
3. Network Layer
• It converts the logical address into the physical address.
• It provides the routing concept means it determines the best route for the packet to travel from source to the destination.
• Some functions of network layer include Routing, Logical addressing, Packetizing, internetworking and Fragmentation.
4. Transport Layer
• It delivers the message through the network by using 2 kinds of services:
A. Connection-oriented transmission: In this transmission, the receiver sends the acknowledgement to the sender after the packet has been received.
B. Connectionless transmission: In this transmission, the receiver does not send the acknowledgement to the sender
• It provides error checking so that no error occurs during the transfer of data.
5. Session Layer
• Its main responsibility is beginning, maintaining and ending the communication between the devices.
• It also reports the error coming from the upper layers.
• It mainly establishes and maintains the session between the two users.
6. Presentation Layer
• It is also known as a Translation layer as it translates the data from one format to another format.
• At the sender side, this layer translates the data format used by the application layer to the common format and at the receiver side, this layer translates the common format into a format used by the application layer.
• The functions of it includes Character code translation, Data conversion, Data compression and Data encryption.
7. Application Layer
• It enables the user to access the network.
• The protocols used in this file are file transfer protocol, simple mail transfer protocol, domain name system, HTTP etc.
What are the common software problems that can lead to network defects?
They are:
• Client-server problems
• Application conflicts
• Error in configuration
• Protocol mismatch
• Security issues
• User policy and rights issues
What is the best place to install an Anti-virus program?
The best place is to install it on all servers and workstations to ensure protection. That’s because individual users can access any workstation and introduce a computer virus. we can plug in their removable hard drives or flash drives.
Differentiate between a router, a hub, and a switch.
HUB:
• It connects two or more ethernet devices.
• It does not perform filtering while transferring the messages.
• It is least intelligent, least expensive, and least complex among all the three
Switch:
• It connects two or more LAN devices in the network.
• It does filter few packets before sending them in the network.
• It is more effective than HUB.
Router:
• It can connect devices on a LAN and WAN.
• It is highly configured to filter and send packets in the network.
• It is the most effective one among all the three.
What is a UTP cable and what can be its maximum length in the network?
It is a 100 ohms cable made up of copper which consists of 2–1800 unshielded twisted pairs that are surrounded by a non-metallic case. The twists provide immunity to electrical noise and EMI. The maximum length of them in the network would be 100 metre where generally 90m is solid cabling and 10 m is the standard patch cable.
What exactly do you understand by the term “piggybacking”?
It refers to the mode of transmission in the network layer which is bi-directional. It is used to improve the efficiency of existing methods. Piggyback acknowledgment (of the received data) is hooked on the data frame (to be sent) instead of sending a separate frame.
What are the different types of transmission modes used in the network?
There are 3 different types of transmission modes used here:
• Simplex Mode: here the communication is unidirectional, as on a one-way street. Only one of the two devices on a link can transmit, the other can only receive.
• Half-duplex Mode: each station can both transmit and receive, but not at the same time.
• Full-duplex Mode: both stations can transmit and receive simultaneously.
Also, while appearing for interview you must be clear with all the full forms of different protocols in networking, hence here I am including all the Important full forms along with the interview questions on networking.
What does SNMP mean?
It stands for simple network management protocol. It is an application layer protocol which uses UDP port number 161/162. It is used to monitor network, detect network faults and sometimes even used to configure remote devices.
What does SMTP mean?
It stands for simple mail transfer protocol. It is an application layer protocol. The client who wants to send the mail opens a TCP connection to the SMTP server and then sends the mail across the connection. The SMTP server is always on listening mode. As soon as it listens for a TCP connection from any client, the SMTP process initiates a connection on that port (25). After successfully establishing the TCP connection the client process sends the mail instantly. In this way SMTP is used for transferring mails between client and server.
In the given URL, http://www.xyz.com what does http stands for?
It stands for hypertext transfer protocol which is an application layer protocol. It uses TCP as an underlying transport and typically runs on port 80. HTTP is a stateless protocol i.e. server maintains no information about past client requests.
How many layers are in TCP/IP?
There are basic 4 layers in TCP/IP:
1. Application Layer
2. Transport Layer
3. Internet Layer
4. Network Layer
Generally, there are two types of model studied in the Networking, name those 2 models and what are the differences between them?
The two models are:
A. TCP/IP model
B. OSI model
The major differences between both are:
We know in networks that URL are in form of ip addresses such as 123.44.67.89/2 but when we search for something in web browsers we use URL of the form www.edvicer.com and so on, so how are this inter-related to each other?
Here we use something known as Domain name system or DNS. It is a naming system for devices connected over the internet. It translates domain names to the numerical IP Addresses which is required to identify and locate devices based on the underlying protocols. All devices connected to the internet have unique IP addresses which are used to locate them on the network. For example, in case the user wants to load some web page (xyz.com), this hostname is converted into an IP address that can be understood by the computer in order to load that web page.
In networking, we often come across the word “ping” while establishing the network, what does this ping command mean?
The “ping” is a utility program that allows you to check the connectivity between the network devices. You can ping devices using its IP address or name.
Differentiate between ‘forward lookup’ and ‘reverse lookup’ in DNS?
Converting names to IP addresses is called forward lookup. Resolving IP addresses to names is called reverse lookup
With this we now come to the end of this top interview questions on networking. Also, I would like you to know that these are the very basics, yet most students get confused here but once you go through all this interview questions on networking, you will have to practice some more numerical and application based questions as you may never know if interviewer asks them too! We won’t be talking about those here, because that would go beyond the scope of this blog.
Thank you, and all the best!!