Internet and Networking Questions for IBPS RRB PO

Types of Networks

Networks are classified by their geographic coverage. Think of it as zoom levels on a map. PAN is your personal bubble, LAN is your office, MAN is your city, WAN is the whole world. The internet itself is the largest WAN. In rural banking context, branch connectivity often uses WAN or VSAT links.

• PAN (Personal Area Network): covers a few meters, e.g. Bluetooth, USB
• LAN (Local Area Network): covers a building or campus, e.g. office network
• MAN (Metropolitan Area Network): covers a city, e.g. cable TV network
• WAN (Wide Area Network): covers countries/globe, e.g. Internet, bank's core banking network
• VSAT (Very Small Aperture Terminal): satellite-based network used in remote/rural branches
• Topology: arrangement of network — Bus, Star, Ring, Mesh (Star is most common in offices)

Network Devices

Network devices are the hardware that connect computers and manage data flow. Each device has a specific job. A hub is a dumb broadcaster, a switch is a smart forwarder, a router finds the best path, and a modem converts digital to analog for telephone lines. Remember: Router routes, Switch switches lanes within a network, Modem modulates.

• Hub: sends data to ALL devices on the network (broadcasts) — Layer 1 device
• Switch: sends data only to the INTENDED device using MAC address — Layer 2 device
• Router: connects different networks and finds best path using IP address — Layer 3 device
• Modem: converts digital signals to analog (for DSL/telephone lines) — MOdulator DEModulator
• Bridge: connects two LAN segments and filters traffic using MAC addresses
• Gateway: connects two different types of networks (acts as a translator)
• Repeater: boosts/regenerates weak signals over long distances

Internet Protocols and Addresses

Protocols are rules for communication, like traffic rules on a highway. IP address is the unique address of every device on a network. IPv4 has 4 sets of numbers (like 192.168.1.1) and IPv6 is the newer longer version. DNS converts website names to IP addresses so you do not have to remember numbers.

• IP (Internet Protocol): unique address for every device — IPv4 is 32-bit, IPv6 is 128-bit
• TCP (Transmission Control Protocol): reliable, connection-oriented data delivery — checks if data arrived
• UDP (User Datagram Protocol): faster but unreliable — used in video streaming, online gaming
• HTTP (HyperText Transfer Protocol): used for web browsing — port 80
• HTTPS: secure version of HTTP with encryption — port 443
• FTP (File Transfer Protocol): used to transfer files — port 21
• DNS (Domain Name System): converts domain name to IP address — like a phonebook of the internet
• SMTP: for sending emails (port 25), POP3/IMAP: for receiving emails

Internet Terminology and Services

The internet is built on several services and technologies. WWW (World Wide Web) is a service on the internet, not the internet itself — a common exam trap. A browser is a software to access the web. URLs have specific parts: protocol, domain, path. Bandwidth is the capacity of a network link, measured in bps (bits per second).

• WWW: collection of web pages linked by hyperlinks — invented by Tim Berners-Lee in 1989
• Browser: software to access internet — Chrome, Firefox, Edge, Safari
• URL (Uniform Resource Locator): web address, e.g. https://www.sbi.co.in
• ISP (Internet Service Provider): company that gives internet access, e.g. BSNL, Jio
• Bandwidth: maximum data transfer rate — higher bandwidth means faster internet
• Firewall: security system that monitors and filters incoming/outgoing network traffic
• VPN (Virtual Private Network): creates a secure encrypted tunnel over internet
• Cookie: small file stored by browser to remember user preferences and sessions

OSI Model Layers

The OSI (Open Systems Interconnection) model has 7 layers describing how data travels from one computer to another. Think of it as a postal system — you write the letter, put it in envelope, address it, hand it to courier, and it travels through roads to destination. IBPS RRB PO occasionally asks which device or protocol belongs to which layer.

• Layer 7 Application: what user sees — HTTP, FTP, SMTP, DNS
• Layer 6 Presentation: data formatting, encryption — JPEG, SSL
• Layer 5 Session: manages sessions/connections
• Layer 4 Transport: reliable delivery — TCP, UDP
• Layer 3 Network: routing, IP addresses — Router works here
• Layer 2 Data Link: MAC addresses, frames — Switch, Bridge work here
• Layer 1 Physical: actual cables, signals — Hub, Repeater work here

• Confusing Internet and WWW — Internet is the global network infrastructure, WWW is just one service running ON the internet. WWW was created by Tim Berners-Lee, Internet was not.
• Mixing up Hub and Switch — Hub sends data to ALL devices (dumb), Switch sends only to the target device (smart). Switch is more efficient and modern.
• Confusing TCP and UDP — TCP is reliable and checks delivery (like registered post), UDP is fast but does not check (like dropping a flyer in mailbox). Streaming uses UDP.
• Thinking IPv4 and IPv6 are the same length — IPv4 is 32-bit (4 octets like 192.168.0.1), IPv6 is 128-bit (much longer, uses hexadecimal). IPv6 was created to solve address shortage.
• Forgetting port numbers — HTTP is port 80, HTTPS is port 443, FTP is port 21, SMTP is port 25. These appear as direct factual questions.

• Network size mnemonic: Please Let Men Win — PAN, LAN, MAN, WAN (smallest to largest coverage)
• OSI layers bottom to top: Please Do Not Throw Sausage Pizza Away — Physical, Data Link, Network, Transport, Session, Presentation, Application
• Device-layer trick: Hub is Helpless (Layer 1), Switch is Smart (Layer 2), Router is Resourceful (Layer 3) — H, S, R in order
• MODEM stands for MOdulator DEModulator — it modulates (converts digital to analog) when sending and demodulates (analog to digital) when receiving. Think of it as a translator between digital computers and analog phone lines.

• IBPS RRB PO Computer section has 40 questions; Internet and Networking typically contributes 2-4 questions. These are pure memory-based so attempt them first to save time.
• Most common question types: identify which device works at which OSI layer, full form of protocol abbreviations, port numbers of common protocols, and definition-based questions on WWW vs Internet.
• Topology questions appear occasionally — Star topology is most common in practice, Bus topology was older, Ring is used in some WANs. Know that Mesh topology is most fault-tolerant.
• Recent papers have included questions on VPN, Firewall, and Cookies — these are modern internet security terms that are trending in exams post-2022.
• Do not spend more than 30-40 seconds per computer question. If you have memorized key terms, these should be the fastest questions in the paper.