Computer Network Tutorial

Introduction of Computer Network Types of Computer Network Network Topology Computer Networking Architecture Transmission Modes (Data Flow) Basic Networking Devices Integrate Services Digital Network (ISDN)


OSI Model TCP/IP Model

Physical Layer

Digital Transmission Analog Transmission Transmission Media Switching

Data Link Layer

Error detection and Error correction Data Link Control Multiple Access Aloha

Network Layer

Network Layer - Logical Address Address Mapping Unicast Routing Protocol

Transport Layer

Process to Process Delivery User Datagram Protocol Transmission Control Protocol Stream Control Transmission Protocol Session Layer and Presentation Layer

Application Layer

Domain Name System Application Protocol E-mail Cryptography

Internet Protocol

Ipv4 vs Ipv6 Supernetting in Network Layer TCP Ports TCP vs UDP TCP TCP Congestion


Differences between IPv4 and IPv6 Difference between Active and Passive FTP Difference between Transport and Network Layer Difference between Star Topology and Bus Topology Difference between BOOTP and RARP Difference Between Network Topologies and Network Protocols Difference between NFC and RFID Difference Between Point-to-Point Link and star Topology Network Differences Between MSS and MTU Differences Between Trunk Port and Access Port Different Modes of Communication in Computer Networks Difference Between Analog and Digital Signals Difference Between Hub and Repeater Difference between Repeater and Switch Difference Between Transparent Bridge and Source Routing Bridge Difference between Border Gateway Protocol (BGP) and Routing Information Protocol (RIP) Difference between GUI Testing and Usability Testing Difference between Sanity Testing and Smoke Testing Differences between Distance Vector and Link State Routing Difference Between Intranet and VPN Difference between VLAN and VSAN


APIPA What is Computer Network What is Framing in a Computer Network What is Bus Topology What is Network Topology and Types in Computer Networks What is a Proxy Server What is APPN What is ICMP Protocol What is Point-to-Point Protocol What is Port Address in Networking What is the HDLC Protocol What is VRRP Protocol What is Wired and Wireless Networking What is a Hardware Firewall What is PAN What is Unit Testing? Why developers should learn Unit Testing What is Data Encapsulation and Data Decapsulation in Networking What is Macro Virus and how they affect Computer Systems What is VLAN What is VSAN What is WSN Network What is Cidr in AWS What are Elementary Data Link Layer Protocols What is An Ad Hoc Network What is The Ieee 802 What is Tunneling in Computer Networks What is Twisted Pair Cable What is a Computer Network What is an ISP


Classes of Routing Protocols Classification of Routing Algorithms Controlled Access Protocols in Computer Networks Fixed and Flooding Routing Algorithms Advantages and Disadvantages of Fibre Optics Cable Fiber Optics and its Types Method of Joining and Fusion of Fiber Optic Cable Define Framing in Computer Network Disadvantages of Computer Network Mesh Topology Diagram in Computer Network Ring Topology in Computer Network Star Topology in Computer Networks 4G Mobile Communication Technology Advantages and Disadvantages of LAN Advantages and Disadvantages of MAN Advantages and Disadvantages of WAN Application Layer in OSI Model Cyclic Redundancy Check Example Data link layer in OSI model Hamming Code Example Network Layer in OSI Model Session Layer in OSI Model Transport Layer in OSI Model Two Port Network in Computer Networks Uses of Computer Networks Advantages and Disadvantages of Bus Topology Subnetting in Computer Network Subnetting Questions and Answers Access Control in Networking Basic Characteristics of Computer Network Benefits of SOCKS5 Proxy in Computer Networks Computer Network viva Questions MIME Protocol in Computer Networks Modes of Communication in Computer Networks Network Attack in Computer Network Port Address in Networking Simplest Protocol in Computer Network Sliding Window Protocol in Computer Network Stop And Wait Protocol in Computer Networks TCP 3-Way Handshake Process in Computer Networks Source Routing Bridge in Computer Networks Transparent Bridge in Computer Networks Transport Protocol in Computer Networks Types of CSMA in Computer Networks Bit Stuffing and Bit De-Stuffing Firewall Methodologies Go Back ARQ in Computer Network Zone Based Firewall Advantages and Disadvantages of Mesh Topology Advantages and Disadvantages of Ethernet Advantages and Disadvantages of Ring Topology Advantages and Disadvantages of the Star Topology Checksum in Networking Delays in Computer Network Functions of Data Link Layer in the OSI Model Go-Back-N ARQ Protocol Guided Transmission Media in Computer Networks IGRP Routing Protocol in Computer Networks Modes Of Bluetooth Connection Protocols of a Network Layer Single Program Multiple Data Data Transfer Instructions with Examples Levels of Cache Memory Logical Addressing in Computer Network Multiple Access Protocols in Computer Network Advantages of Unguided Media Back Side Bus in Computer Network Router and Brouter in Computer Network 2 Dimension Parity Check in Computer Network Data Link Layer Services Provided to the Network Layer Functions Of the Transport Layer Computer Network Security Requirements Transmission Impairments in Computer Networks Types of Modems Microwave Transmission in Computer Networks Brust Errors In Computer Network Digital Signal in Computer Network Network Security Requirements Router in Computer Network Check Sum Error Detection Checksum Example Infrared Transmission in Computer Networks Linear Bus Topology Magnetic Media in Computer Network Digital Data Transmission in Computer Networks Advantages and Disadvantages of Routers Advantages of Installing a Network Application Layer in Computer Networks Application Layer Protocols in Computer Networks Application of Data Communication Network Central Device in Star Topology Multiple Access Techniques in Wireless Communication Parallel Port in Computer Resource Sharing in Computer Networks Static Routing Algorithms in Computer Network TDMA Technology Advantages and Disadvantages of Networking ATM Network Authentication in Computer Network Automatic Repeat Request Arq Characteristics of Digital Signals Cim Data Transmission Methods Components of Data Communication in Computer Network Disadvantages of Tree Topology DVRMP in Computer Network Mac Layer Functions and Protocol Pros and Cons of Extranet Protocol and its Types Resource Sharing in Computer Network Simplex Data Transmission in Computer Network Top 10 Benefits of Computer Networking Types of Computer Buses Unguided Media

Domain Name System in Computer Network

Domain Name System

Domain Name System is also called DNS. DNS was introduced by Paul Mockapetris and Jon Postel in 1983. DNS is an internet service that converts Domain names to IP addresses. When the user types any domain name in a web browser, then the DNS server converts that domain name to IP address.

Domain Name System

For example - When a user types in a web browser, DNS changes it to an IP address Now you see for yourself how easy it is to remember, while how difficult it is to remember the IP address

If one DNS server does not convert the domain name, it asks the other DNS server to convert the domain name, and the process continues until the domain name will be converted.

DNS in the Internet

On the internet, DNS is a protocol. It is used on various platforms. The tree of the domain name system is divided into three categories: generic domains, country domains, and the inverse domains.

Domain Name System

Generic Domains

It defines the registered hosts by their common actions. Every node of the tree represents a domain. It is an index of the DNS database that is shown in the figure below.

Domain Name System

It gives the 14 possible labels. The description of these labels is shown in the table.

aeroAirlines and aerospace companies
bizBusinesses or firms (similar to “com”)
comCommercial organizations
coopCooperative business organizations
eduEducational institutions
govGovernment institutions
infoInformation service providers
intInternational organizations
milMilitary groups
museumMuseums and other nonprofit organizations
namePersonal names (individuals)
netNetwork support centers
orgNonprofit organizations
proProfessional individual organizations

Country Domains

The country domain uses only two characters for the country abbreviations, such as (in = India). In the country domain, second labels can be organizational.

For example,


  • TMU represents the name of the organization.
  • is represented the country domains ( means academia of India).

This example is better understood in the figure below.

Domain Name System

Inverse Domain

The inverse domains are those domain name system that is used to map an IP address to a domain name. The example of the inverse domain is shown in the figure below.

Domain Name System