CIDR Practice Question_

Duration: 3 min

This video lesson is available to enrolled students.

Return to /learn/HPSC-PGT-COMPUTER-SCIENCE/computer-networks/net-layer-ip-addressing/cidr-vlsm/asset-cidr-practice-question-4748 after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. HPSC Interview Preparation: Interview Preparation
  2. Python Language: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis, DSA using Python
  3. Data Structure & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Sorting Algorithms, Minimum Spanning Trees, Time Complexity Analysis, Graph Theory, Shortest Path Algos
  4. Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security
  5. Computer System & Organisation: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer
  6. Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Transaction Management, Concurrency Control
  7. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling
  8. Digital Logic & Circuits: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  9. Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Pushdown Automata & CFG, Turing Machines, Moore & Mealy Machines
  10. Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  11. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, Data Warehousing & Mining
  12. Introduction to Emerging Trends: Emerging Tech Trends
  13. Digital Society & Cyber Law: Society, Law & Ethics
  14. HPSC PGT Previous Year Paper:
  15. HPSC Assistant Professor Previous Year Paper:
  16. Live Sessions: HPSC Live Sessions, EMRS TGT/PGT Live Class
  17. Full Mock Test:
  18. HPSC PGT - MOCK Test Series:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The lecture focuses on validating and representing a specific range of IP addresses as a Classless Inter-Domain Routing (CIDR) block. The instructor presents a problem involving the range 150.10.20.64 to 150.10.20.127 and systematically applies three specific rules to determine validity. He calculates the total number of addresses, verifies it is a power of two, and checks the divisibility of the starting address. Finally, he derives the subnet mask length by calculating the necessary host bits to complete the CIDR notation.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor introduces the problem statement on screen: 'Consider a block of IP Addresses ranging from 150.10.20.64 to 150.10.20.127'. He lists three rules for CIDR blocks: contiguity, power-of-two size, and divisibility of the first address. He calculates the block size using the formula 127 - 64 + 1, resulting in 64. He lists powers of 2 (2, 4, 8, 16, 32, 64) to confirm 64 is valid. He then checks the third rule by dividing the first address (64) by the block size (64), noting the remainder is zero. He concludes the block is valid. He emphasizes that the first address must be divisible by the size to ensure the host ID ranges from all 0s to all 1s.

  2. 2:00 – 3:00 02:00-03:00

    The instructor proceeds to find the CIDR representation. He draws a 32-bit IP structure divided into Network ID and Host ID. Since the block size is 64, he determines that 6 bits are required for the host portion because 2^6 = 64. He subtracts these 6 host bits from the total 32 bits to find the network prefix length: 32 - 6 = 26. He writes the final CIDR notation as 150.10.20.64/26. He briefly sketches the binary values for the last octet to illustrate the range from 01000000 to 01111111. He explains that the network ID remains constant while the host ID varies across the block.

The lesson demonstrates a step-by-step algorithm for CIDR validation. First, calculate the total count of addresses. Second, verify the count is a power of 2. Third, ensure the starting address is a multiple of that count. Once validated, the host bits are derived from the log base 2 of the block size, and the prefix length is the remainder of 32 minus the host bits. This process ensures the IP block is aligned correctly within the address space.

Loading lesson…