Computer Network for IBPS SO IT Preparation
Computer Network is one of the most important subjects for IBPS SO IT preparation. In the Professional Knowledge section, questions can be asked from network basics, OSI model, TCP/IP model, IP addressing, protocols, network devices, transmission media, switching, routing, network security, and internet concepts.
A computer network is a group of connected computers and devices that can share data, resources, and services. These resources may include files, printers, internet connection, databases, applications, and servers.
In simple words, when two or more computers are connected to communicate with each other, it is called a computer network.
What is Computer Network?
A computer network is a system where computers, servers, routers, switches, and other devices are connected together to exchange data and share resources. The main purpose of a network is communication and resource sharing.
For example, when you send an email, use online banking, browse a website, access cloud storage, or use UPI payment, computer networking works in the background.
Why Computer Network is Important for IBPS SO IT?
Computer Network is important for IBPS SO IT because banking systems depend heavily on secure communication, servers, databases, internet connectivity, ATMs, mobile banking, net banking, and payment gateways. An IT Officer should understand basic networking concepts to manage and troubleshoot banking IT systems.
Basic Components of Computer Network
Component Meaning Sender The device that sends data. Receiver The device that receives data. Message The data or information being transferred. Transmission Medium The path through which data travels, such as cable or wireless signal. Protocol A set of rules used for communication between devices.
Advantages of Computer Network
Computer networks help in resource sharing, fast communication, centralized data management, easy backup, remote access, cost reduction, and better collaboration. In banks, networking helps connect branches, ATMs, servers, and online banking services.
Disadvantages of Computer Network
Computer networks may face security risks, virus attacks, hacking, high setup cost, dependency on network devices, and performance issues if the network is not properly managed.
Types of Computer Networks
Computer networks are classified based on geographical area and size. The main types are PAN, LAN, MAN, and WAN.
Network Type Full Form Coverage Area Example PAN Personal Area Network Very small area around a person Bluetooth connection between phone and earbuds LAN Local Area Network Small area like home, lab, office, or building Office network MAN Metropolitan Area Network City-level area Network connecting different branches in a city WAN Wide Area Network Large geographical area Internet
Network Topology
Network topology means the arrangement of devices in a computer network. It defines how nodes are connected and how data flows between them.
Topology Meaning Main Point Bus Topology All devices are connected to a single main cable. Simple but failure of main cable affects whole network. Star Topology All devices are connected to a central hub or switch. Most commonly used in LAN. Ring Topology Devices are connected in circular form. Data travels in a ring direction. Mesh Topology Each device is connected to many or all other devices. High reliability but expensive. Tree Topology Combination of star and bus topology. Used in hierarchical networks. Hybrid Topology Combination of two or more topologies. Used in large organizations.
OSI Model
OSI stands for Open Systems Interconnection. It is a reference model used to understand how data communication happens in a network. The OSI model has seven layers.
The seven layers of OSI model are Physical, Data Link, Network, Transport, Session, Presentation, and Application.
Layer Number Layer Name Main Function Examples 7 Application Layer Provides network services to users. HTTP, FTP, SMTP, DNS 6 Presentation Layer Handles data formatting, encryption, and compression. JPEG, SSL, encryption 5 Session Layer Manages sessions between applications. Session management 4 Transport Layer Provides end-to-end delivery and reliability. TCP, UDP 3 Network Layer Handles logical addressing and routing. IP, ICMP, routers 2 Data Link Layer Handles framing, MAC addressing, and error detection. Switch, Ethernet, MAC 1 Physical Layer Transmits raw bits over physical medium. Cables, hubs, signals
Mnemonic for OSI Model
From top to bottom, remember: All People Seem To Need Data Processing.
Application, Presentation, Session, Transport, Network, Data Link, Physical.
TCP/IP Model
TCP/IP model is the practical model used on the internet. It has four layers: Application Layer, Transport Layer, Internet Layer, and Network Access Layer.
TCP/IP Layer Function Related Protocols Application Layer Provides network applications and services. HTTP, HTTPS, FTP, SMTP, DNS Transport Layer Provides process-to-process communication. TCP, UDP Internet Layer Handles logical addressing and routing. IP, ICMP, ARP Network Access Layer Handles physical transmission and local network access. Ethernet, Wi-Fi
Difference Between OSI Model and TCP/IP Model
Basis OSI Model TCP/IP Model Full Form Open Systems Interconnection Transmission Control Protocol/Internet Protocol Number of Layers 7 layers 4 layers Nature Reference model Practical internet model Usage Used mainly for understanding networking concepts Used in real-world internet communication Development Developed before protocols Developed with protocols
Transmission Media
Transmission media is the path through which data travels from sender to receiver. It can be guided or unguided.
Type Medium Example Guided Media Data travels through physical cables. Twisted pair cable, coaxial cable, optical fiber Unguided Media Data travels through wireless signals. Radio waves, microwaves, infrared, satellite
Guided Transmission Media
Twisted pair cable is commonly used in LAN and telephone networks. Coaxial cable provides better shielding than twisted pair. Optical fiber uses light signals and provides very high speed, long-distance communication, and low signal loss.
Unguided Transmission Media
Unguided media uses wireless communication. Radio waves are used in Wi-Fi and broadcasting. Microwaves are used in long-distance communication. Infrared is used for short-range communication. Satellite communication is used for wide coverage.
Network Devices
Network devices are hardware devices used to connect, control, and manage communication between network nodes.
Device Layer Function Repeater Physical Layer Regenerates weak signals. Hub Physical Layer Broadcasts data to all connected devices. Bridge Data Link Layer Connects and filters traffic between LAN segments. Switch Data Link Layer Forwards frames using MAC address. Router Network Layer Routes packets using IP address. Gateway Multiple Layers Connects different types of networks. Modem Physical/Data Link Converts digital signal to analog and analog to digital. Firewall Network/Security Controls incoming and outgoing network traffic.
Hub vs Switch vs Router
Device Works On Address Used Main Use Hub Physical Layer No address Broadcasts data to all devices. Switch Data Link Layer MAC Address Connects devices within LAN. Router Network Layer IP Address Connects different networks.
IP Addressing
An IP address is a logical address assigned to a device on a network. It is used to identify devices and route data from source to destination.
There are two main versions of IP address: IPv4 and IPv6.
Feature IPv4 IPv6 Address Size 32-bit 128-bit Format Decimal numbers separated by dots Hexadecimal numbers separated by colons Example 192.168.1.1 2001:0db8:85a3::8a2e:0370:7334 Address Space Limited Very large
IP Address Classes
Class Range Default Subnet Mask Use Class A 1 to 126 255.0.0.0 Large networks Class B 128 to 191 255.255.0.0 Medium networks Class C 192 to 223 255.255.255.0 Small networks Class D 224 to 239 Not applicable Multicasting Class E 240 to 255 Not applicable Experimental use
Important IP Address Points
127.0.0.1 is called the loopback address. It is used to test the local machine. 0.0.0.0 usually represents an unspecified address. 255.255.255.255 is used as a broadcast address in IPv4.
Public IP and Private IP
A public IP address is used on the internet and is globally unique. A private IP address is used inside a private network such as home, office, or organization network.
Private IP Class Private IP Range Class A 10.0.0.0 to 10.255.255.255 Class B 172.16.0.0 to 172.31.255.255 Class C 192.168.0.0 to 192.168.255.255
Subnetting
Subnetting is the process of dividing a large network into smaller logical networks called subnets. It helps in better IP address management, improved security, reduced broadcast traffic, and efficient network performance.
MAC Address
MAC address stands for Media Access Control address. It is a physical address assigned to a network interface card. It is used at the Data Link Layer. A MAC address is usually 48 bits long.
TCP and UDP
TCP and UDP are transport layer protocols. TCP is connection-oriented and reliable. UDP is connectionless and faster but less reliable.
Basis TCP UDP Full Form Transmission Control Protocol User Datagram Protocol Connection Connection-oriented Connectionless Reliability Reliable Less reliable Speed Slower than UDP Faster than TCP Error Control Provides error control and retransmission No proper retransmission mechanism Example Use Web browsing, email, file transfer Video streaming, online gaming, VoIP
Important Network Protocols
Protocol Full Form Use Default Port HTTP HyperText Transfer Protocol Used for web communication 80 HTTPS HyperText Transfer Protocol Secure Secure web communication 443 FTP File Transfer Protocol File transfer 20, 21 SMTP Simple Mail Transfer Protocol Sending emails 25 POP3 Post Office Protocol version 3 Receiving emails 110 IMAP Internet Message Access Protocol Accessing emails from server 143 DNS Domain Name System Converts domain name to IP address 53 DHCP Dynamic Host Configuration Protocol Automatically assigns IP address 67, 68 SSH Secure Shell Secure remote login 22 Telnet Teletype Network Remote login without encryption 23 SNMP Simple Network Management Protocol Network device management 161
DNS
DNS stands for Domain Name System. It converts human-readable domain names into IP addresses. For example, when a user enters a website name in the browser, DNS helps find the IP address of that website server.
DHCP
DHCP stands for Dynamic Host Configuration Protocol. It automatically assigns IP address and other network configuration details to devices in a network.
ARP
ARP stands for Address Resolution Protocol. It is used to find the MAC address of a device when its IP address is known.
ICMP
ICMP stands for Internet Control Message Protocol. It is used for error reporting and diagnostic purposes. The ping command uses ICMP.
Switching
Switching is the process of forwarding data from source to destination within a network. There are mainly three types of switching: circuit switching, packet switching, and message switching.
Switching Type Meaning Example Circuit Switching A dedicated path is established before communication. Traditional telephone network Packet Switching Data is divided into packets and sent independently. Internet Message Switching Complete message is stored and forwarded. Older communication systems
Routing
Routing is the process of selecting the best path for data packets to travel from source to destination. Routers perform routing using routing tables and routing protocols.
Routing Protocols
Common routing protocols include RIP, OSPF, BGP, and EIGRP. RIP uses hop count as metric. OSPF uses cost as metric. BGP is used for routing between autonomous systems on the internet.
Client-Server and Peer-to-Peer Network
Basis Client-Server Network Peer-to-Peer Network Structure Central server provides services to clients. All devices can act as both client and server. Management Centralized management Decentralized management Security More secure and controlled Less secure compared to client-server Example Banking server and client systems Small file sharing network
Network Security
Network security means protecting network devices, data, and communication from unauthorized access, misuse, modification, and attacks. It is very important in banking systems because banks handle sensitive customer and financial data.
Important Network Security Terms
Term Meaning Firewall Filters incoming and outgoing network traffic. VPN Creates a secure encrypted connection over public network. Encryption Converts data into unreadable form to protect it. Authentication Verifies the identity of a user or device. IDS Intrusion Detection System detects suspicious activity. IPS Intrusion Prevention System detects and blocks threats. Malware Malicious software designed to harm systems. Phishing Fraud technique used to steal sensitive information.
Bandwidth, Latency and Throughput
Bandwidth is the maximum data carrying capacity of a network. Latency is the delay in data transmission. Throughput is the actual amount of data transferred successfully in a given time.
Term Meaning Bandwidth Maximum capacity of a network link. Latency Delay between sending and receiving data. Throughput Actual data transferred successfully. Jitter Variation in packet delay.
Important Computer Network Exam Points for IBPS SO IT
Topic Must Remember Point Computer Network It connects devices for communication and resource sharing. LAN Covers a small area like office or building. WAN Covers a large geographical area. Internet is the best example. OSI Model It has 7 layers. TCP/IP Model It has 4 layers and is used in real internet communication. Switch Works at Data Link Layer and uses MAC address. Router Works at Network Layer and uses IP address. TCP Connection-oriented and reliable protocol. UDP Connectionless and faster protocol. DNS Converts domain names into IP addresses. DHCP Automatically assigns IP addresses. ARP Finds MAC address from IP address. ICMP Used for error reporting and ping command. HTTPS Secure version of HTTP and uses port 443. FTP Used for file transfer.
Common Mistakes Students Make in Computer Network
Many students confuse switch and router. A switch connects devices within the same network and uses MAC address, while a router connects different networks and uses IP address.
Students also confuse TCP and UDP. TCP is reliable and connection-oriented, while UDP is faster and connectionless.
Another common mistake is confusion between DNS and DHCP. DNS converts domain names to IP addresses, while DHCP automatically assigns IP addresses to devices.
How to Prepare Computer Network for IBPS SO IT
First, study the basics of networks, types of networks, and network topologies. After that, focus on OSI model and TCP/IP model because they are highly important for exams. Then learn IP addressing, protocols, network devices, switching, routing, and security concepts.
Make short notes of protocols and port numbers. Revise important differences such as TCP vs UDP, hub vs switch vs router, OSI vs TCP/IP, IPv4 vs IPv6, and public IP vs private IP.
Practice Computer Network Quiz
After reading this article, practice MCQs to check your preparation level. Attempt the Computer Network quiz here: Start Computer Network Quiz
Conclusion
Computer Network is a very important subject for IBPS SO IT preparation. Students should focus on OSI model, TCP/IP model, IP addressing, network devices, protocols, port numbers, switching, routing, and network security. With regular revision and MCQ practice, this topic can help improve your score in the Professional Knowledge section.
Frequently Asked Questions on Computer Network
What is a computer network?
A computer network is a group of connected computers and devices that can communicate and share resources with each other.
What are the main types of computer networks?
The main types of computer networks are PAN, LAN, MAN, and WAN.
How many layers are there in the OSI model?
There are seven layers in the OSI model: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
How many layers are there in the TCP/IP model?
The TCP/IP model has four layers: Application Layer, Transport Layer, Internet Layer, and Network Access Layer.
What is the difference between TCP and UDP?
TCP is connection-oriented and reliable, while UDP is connectionless and faster but less reliable.
What is DNS?
DNS stands for Domain Name System. It converts domain names into IP addresses.
What is DHCP?
DHCP stands for Dynamic Host Configuration Protocol. It automatically assigns IP addresses to devices in a network.
What is the function of a router?
A router connects different networks and forwards data packets using IP addresses.
What is the function of a switch?
A switch connects devices within a LAN and forwards frames using MAC addresses.
Is Computer Network important for IBPS SO IT?
Yes, Computer Network is very important for IBPS SO IT because many questions can be asked from OSI model, TCP/IP model, IP addressing, protocols, networking devices, and security concepts.
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