Top 100 Networking Interview Questions with Answers

This tutorial presents 100 basic networking interview questions with detailed answers. These questions and answers will help you face a networking interview confidently.

Q1:- What is the difference between physical topology and logical topology?

A physical topology describes how computers connect physically, whereas a logical topology describes how devices transmit data over a physical topology.

Q2:- What is a cookie?

A cookie is a small piece of information that a website stores on a user's browser for various purposes such as tracking, advertising, etc.

Q3:- What is an IP address?

An IP address is a unique identity of an interface on an IP network. It consists of 32 bits. It divides these bits into four equal sections. It uses dots to separate sections. It writes sections in a sequence.

Q4:- What is the difference between baseband technology and broadband technology?

Baseband technology uses bidirectional digital signals for transmission. It uses a single channel to send and receive data. Broadband technology uses unidirectional analogue signals for transmission. It uses two separate channels to send and receive the data.

Q5:- What is a Bandwidth?

Bandwidth is the amount of data that a cable can carry. To compute it, subtract the lower frequency of data signals from the higher one. We measure digital signals in bps (bits per second) and analogue in Hz (Hertz).

Q6:- What is the use of ARP and RARP in a network?

In a LAN network, a node needs two addresses (IP address and MAC address) to communicate with others. When it has only one address and requires another, it uses ARP and RARP. It uses ARP when it has an IP address and needs the MAC address. It uses RARP when it has a MAC address and needs the IP address.

Q7:- What is the auto responder in the email system?

In an email system, the autoresponder is a service that automatically sends a prewritten answer email to the sender as soon as it receives the email.

Q8:- What is a junk email?

A junk mail is an unsolicited mail. Usually, it contains newsletters or advertising content. It arrives from an address not listed in the address book.

Q9:- What is a packet sniffer?

A packet sniffer is a program or device that captures data packets from the wire.

Q10:-What is Telnet?

Telnet allows a user to access the system or device remotely.

Q11:- In the OSI model, what is Encapsulation?

Encapsulation is the process of preparing data for transmission. In this process, first, the data is encrypted and compressed. Later, it moves through the layers. Each layer adds its individual information in the header. In transmission, this information is read and used by various devices and protocols to deliver the data packet to the correct destination.

Q12:- In the OSI model, what is Decapsulation?

Decapsulation is the process of extracting original data from an encoded data packet. A data packet received from the network contains several headers. Decapsulation removes these headers, decrypts data, and decompresses the decrypted data to reassemble the original data.

Q13:- What is ANSI?

ANSI stands for American National Standards Institute. It is an organization that officially defines standards in America. The official website of ANSI is www.ansi.org.

Q14:- Which layers in the OSI model are known as lower layers?

Physical, Data-Link, and Network layers are known as lower layers.

Q15:- Which are the upper layers in the OSI model?

The upper layers are Application, Presentation, Session, and Transport.

Q16:- What do the extensions .com, .net, .org, .info, .biz, and .in stand for?

The extensions .com, .net, .org, .info, .biz, and .in stand for commercial, network, organization, information, business and India, respectively.

Q17:- What is a MAC address?

A MAC address is the physical address of a NIC. It is 48 bits in length.

Q18:- What does a router use to determine the best path to a destination?

A router uses the routing table to determine the best path to the destination.

Q19:- What is used on the Internet to find the IP address of a computer host that resides on the Internet?

DNS server

Q20:- What is a daemon?

A daemon is an application or a process that runs on a server to provide client and server access and communication.

Q21:- Which functionality disguises IP addresses seen on the Internet?

NAT (Network Address Translation)

Q22:- Which protocol resolves IP addresses to hardware addresses?

ARP (Address Resolution Protocol)

Q23:- What is a proprietary standard?

A proprietary standard is a standard that is developed and owned by a specific vendor.

Q24:- What is a de-facto standard?

A de facto standard is a standard that began as a proprietary standard and then grew to a standard that everyone uses.

Q25:- What is the maximum collision rate in a healthy Ethernet LAN?

The collision rate should not be more than 30% in a healthy Ethernet.

Q26:- Which devices examine a broadcast on the Ethernet LAN?

All devices on the network examine a broadcast message.

Q27:- Is the broadcast message intended for a specific device on the network?

No, a broadcast message is for all devices on the network.

Q28:- What does OSI stand for?

OSI stands for Open System Interconnection.

Q29:- What does FTP stand for?

FTP stands for File Transfer Protocol.

Q30:- What does DHCP stand for?

DHCP stands for Dynamic host configuration protocol.

Q31:- What is a router?

A router is a device that connects different networks.

Q32:- What is an MAU?

An MAU (Multi-station Access Unit) is a topology-specific Hub. In terms of functionalities and characteristics, it works similarly to a Hub but is used only in the token ring.

Q33:- Which is the bottom layer of the OSI model?

The physical layer is the bottom layer of the OSI model.

Q34:- Which is the topmost layer of the OSI model?

The application layer is the topmost layer of the OSI model.

Q35:- What does the term driver refer to?

A driver is a software that contains technical information about a specific device. This information includes what the device is, how it works on the system, and what it needs to communicate and coexist with other devices.

Q36:- Are 10Base2 and 10Base5 Ethernet architectures used on a modern network?

No, both architectures define cable standards for a bus topology that is outdated and no longer used in modern networks.

Q37:- Which topology uses 10BaseT architecture?

Star topology uses 10BaseT architecture. It provides a maximum of 10 Mbps speed. It uses Baseband transmission technology and UTP (CAT-3) cable.

Q38:- How does removing a T connector affect a network built on bus topology?

Removing a T connector affects only the attached node. It does not interrupt the signal flow on the main cable. Therefore, the remaining nodes have no effect.

Q39:- What is a drop cable?

A drop cable is a cable that connects a workstation with a backbone cable in bus topology.

Q40:- What is the maximum length of Thicknet coaxial cable?

The maximum length of Thicknet coaxial cable is 500 meters.

Q41:- Which cable is known as the RG58 cable?

The Thinnet cable is known as the RG58 cable.

Q42:- Why is coaxial cable no longer used in computer networks?

Bus topology uses coaxial cable. It is outdated. Modern networks do not use it. Modern networks use star topology. Star topology uses twisted pair cables.

Q43:- What is the maximum distance of a UTP cable?

The maximum distance of a UTP cable is 100 meters.

Q44:- Which connector connects the UTP cable with the NIC?

An RJ45 connector connects the UTP cable with the NIC.

Q45:- Which cable uses an RJ11 connector?

The telephone cable (2 pairs, four wires, CAT1) uses an RJ11 connector.

Q46:- Can we use the Cateogry1 (UTP) cable for data transmission?

We can not use the Cateogry1 (UTP) cable for data transmission. It has only four wires (2 pairs). With four wires, a cable can transmit either data or voice. It can not transmit both simultaneously. Earlier, telephone networks used it for voice transmission.

Q47:- Which port does PING use?

PING does not use any port. Any application that operates in layer 4 needs a port. Since PING is a layer three network management tool, it does not require a port to operate.

Q48:- Which topology uses a centralized device for connectivity?

Star topology uses a centralized device (HUB or Switch) for connectivity.

Q49:- Which topology uses coaxial cable and terminators?

Bus topology uses coaxial cables and terminators.

Q50:- What is the daisy-chaining technique, and which topology uses this technique?

Star topology uses the daisy-chaining technique to extend the network. In this technique, a hub or switch connects to another hub or switch as the node of the existing topology. Then, that hub or switch connects more devices in the network.

Q51:- What is the signal bouncing issue, and how can it be solved?

A signal bouncing issue occurs in bus topology. Bus topology uses a coaxial cable to connect the computers. In this topology, when a computer sends a signal, the signal travels in both directions from the sending computer. When this signal reaches the end of the cable, it bounces back and returns in the original direction. This issue is known as a signal-bouncing issue. Terminators at both ends solve this issue. A terminator absorbs the signals when they reach it. It resolves the signal-bouncing issue.

Q52:- What is the backbone network?

The network which connects two or more networks is considered a backbone network. Usually, the backbone network contains high-speed data-transferring devices such as routers and switches. It connects the network, which provides end-user connectivity.

Q53:- What is the PAN network, and how is it different from the LAN network?

A PAN network is the shorter version of a LAN network. A LAN network is for a group of users. It includes multiple computers connected for data sharing. A PAN network is for a single user. It connects personal devices such as smartphones, laptops, printers, and scanners with the user's computer.

Q54:- A company has offices in Jaipur and Delhi. What type of computer network will it use to connect these offices?

WAN (Wide Area Network) connects networks spread over different geographical locations.

Q55:- A company does not have a sufficient budget for lease line connection. Which cost-effective alternate will you suggest for the company?

VPN (Virtual Private Network) is a cost-effective alternative for a leased line.

Q56:- A company wants to extend its intranet network to certain business partners. What type of network will it use?

It will use an extranet. An extranet extends the intranet.

Q57:- How many wires does the UTP cable contain?

UTP cable contains four pairs of wires. Each pair has two wires twisted with each other. This way, there are eight wires in a UTP cable.

Q58:- how many wires in a UTP cable transmit data?

Four out of eight wires transmit data in a UTP cable.

Q59:- in a UTP cable, which wires transmit data?

Wires 1, 2, 3, and 6 transmit data. Wire 1 and 2 create a circuit to send data, whereas wires 3 and 6 create a circuit to receive data.

Q60:- What is the maximum data transmission speed of Category 5 UTP cable, Category 5e UTP cable, and Category 6 UTP cable?

The maximum transmission speeds of Category 5 UTP cable, Category 5e UTP cable, and Category 6 UTP cable are 100Mbps, 1000Mbps, and 10Gbps, respectively.

Q61:-Which networks use cables: RG58 & RG8 and RG59 & RG6?

computer networks use RG58 and RG8 cables. TV cable networks use RG59 and RG6 cables.

Q62:- Can we use RG59 and RG6 cables in computer networks?

We can not use RG59 and RG6 cables in computer networks. These cables are for cable TV networks.

Q63:- Are coaxial cables still used in computer networks?

No, modern networks use twisted pair cables.

Q64:- What is the maximum data transmission speed of Category 2 UTP cable, Category 3 UTP cable, and Category 4 UTP cable?

The maximum transmission speed of Category 2 UTP cable, Category 3 UTP cable, and Category 4 UTP cable is 4 Mbps, 10 Mbps, and 16 Mbps, respectively.

Q65:- What is 802.3, and what does it define?

IEEE 802.3 is a collection of IEEE standards. It defines standards for the Physical layer, including access methods used in the Data Link Layer.

Q66:- What is the 5-4-3 rule, and in which architecture is it used?

10Base2 and 10Base5 Ethernet architectures use the 5-4-3 rule. In this rule, a maximum of five segments in a network can connect with four repeaters. Of these five segments, only three can have nodes.

Q67:- What does 10Base2 stand for?

In a 10Base2 architecture, 10 stands for speed, Base stands for Baseband transmission, and 2 stands for 200 meters (The maximum distance it can span).

Q68:- What are the differences between TCP and physical ports?

A TCP port is a logical number. The transport layer uses it for connection multiplexing. Connection multiplexing process maps a local process with a remote node using port numbers.
A physical port is the connection point of a node. An external device or cable connects with the node on this port.

Q69:- What is a Link?

A Link is a physical or logical connection between two nodes on the network.

Q70:- What is a Node?

In a network, any device or system with an NIC and an IP address to communicate with other NICs is considered a node.

Q71:- List five applications that use the TCP port.

Telnet, FTP, SSH, SMTP, and POP.

Q72:- What are the two sub-layers of the Data Link layer?

Logical Link Control (LLC) and Media Access Control (MAC).

Q73:- What technology creates a point-to-point network connection over the Internet?

VPN (a virtual private network).

Q74:- What does NIC stand for?

The NIC stands for the network interface controller.

Q75:- In which layers of the OSI model does a NIC operate?

NIC operates in layer one and layer 2 of the OSI model.

Q76:- Which Ethernet architectures use a BNC connector?

10Base2 and 10Base5 Ethernet architectures use BNC connectors.

Q77:- Which cable standard uses the CSMA/CD access method?

10BASE5 standard uses the CSMA/CD access method.

Q78:- How many network segments can we have in 10Base2?

We can populate a maximum of three network segments in 10Base2.

Q79:- Which cable type does 10BaseFL network use?

10BaseFL network uses Fiber optical cables.

Q80:- What is the maximum length of a ThinNet cable?

The maximum length of a ThinNet cable is 185 meters.

Q81:- Which cable is known as the RG8 cable?

The Thicknet cable is known as the RG8 cable.

Q82:- Which cable type is the backbone of bus topology?

The backbone cable type in bus topology is the Thicknet (RG8).

Q83:- What does ISO stand for?

ISO stands for International Organization for Standardization.

Q84:- What does OSI stand for?

OSI stands for Open System Interconnection.

Q85:- What is the OSI layer model?

OSI Layer model is a logical structure that defines the data transmission process from one computer to another.

Q86:- How many layers are there in the OSI model?

There are seven distinct layers in the OSI model. The names of these layers are Physical, Data Link, Network, Transport, Session, Presentation, and Application.

Q87:- What is a unicast message?

A unicast message is a message that is sent to a specific address and intended for a particular node in the network.

Q88:- What is a multicast message?

A multicast message is a message that is sent on a multicast address and intended for a group of nodes on the network.

Q89:- What is a broadcast message?

A broadcast message is a message that is sent to a broadcast address and intended for all nodes on the network.

Q90:- What does the standard IEEE802.3ab define?

The IEEE802.3ab standard defines 1000BaseTX Ethernet implementation. 1000BaseTX uses UTP (CAT 5e or CAT6) cable. It provides a speed of 1000Mbps. It supports a maximum distance of 100 meters.

Q91:- What is a Mail Gateway?

The system performs a protocol translation between different electronic mail delivery protocols.

Q92:- Which network does VPN use for data transportation?

VPNs use public networks such as the Internet to transport data.

Q93:- What is the use of tunneling protocols in VPN?

In VPN, tunnelling protocols encrypt and decrypt data.

Q94:- How many classes are there in IPv4?

In IPv4, there are five classes.

Q95:- What are the IP ranges in IPv4?

Q96:- What does the term Pipelining describe?

The term Pipelining describes the sequencing of processes. When a new task begins immediately after the current one ends, it is called sequencing.

Q97:- What is the difference between Baseband and Broadband transmission?

Baseband transmission transmits only one signal at a time. Broadband transmission transmits multiple signals simultaneously.

Q98:- What does the SLIP stand for?

The SLIP stands for Serial Line Interface Protocol. It is used in WAN technology to transmit IP datagrams over a serial line.

Q99:- Which measurement unit measures the transmission speed of Ethernet?

Mbps (millions of bits per second) unit measures the transmission speed of Ethernet.

Q100:- What are the key elements of a protocol?

A protocol is a set of rules governing all aspects of information communication. A protocol has three key elements: Syntax, Semantics, and Timing. Syntax defines the data format. Semantics describes the data bits of each section. Timing controls what time and how fast data is transmitted.