computer networks part -4

Question: GCD is used to:

Options:

(A) Encrypt data

(B) Find key relationships

(C) Compress data

(D) Route packets

Correct Answer: (B) Find key relationships

Question: Modular inverse is essential for:

Options:

(A) Decryption process

(B) Routing tables

(C) Hashing only

(D) Data storage

Correct Answer: (A) Decryption process

Question: Euler's totient function helps in:

Options:

(A) Addressing

(B) Key generation

(C) Data transfer

(D) Routing

Correct Answer: (B) Key generation

Question: Fermat's theorem contributes to:

Options:

(A) Network speed

(B) Cryptographic hardness

(C) Storage efficiency

(D) Compression

Correct Answer: (B) Cryptographic hardness

Question: Computational complexity resists:

Options:

(A) Routing loops

(B) Brute-force attacks

(C) Packet loss

(D) Latency

Correct Answer: (B) Brute-force attacks

Question: Exponentiation is heavily used in:

Options:

(A) Symmetric encryption

(B) Asymmetric encryption

(C) Routing

(D) Switching

Correct Answer: (B) Asymmetric encryption

Question: Cryptographic strength depends on:

Options:

(A) Key secrecy only

(B) Mathematical difficulty

(C) Bandwidth

(D) CPU speed

Correct Answer: (B) Mathematical difficulty

Question: Modular reduction prevents:

Options:

(A) Overflow

(B) Encryption

(C) Hashing

(D) Routing

Correct Answer: (A) Overflow

Question: Public key systems rely on:

Options:

(A) Simple arithmetic

(B) Complex number theory

(C) Analog math

(D) Linear algebra only

Correct Answer: (B) Complex number theory

Question: Arithmetic operations in cryptography are:

Options:

(A) Random

(B) Deterministic

(C) Analog

(D) Approximate

Correct Answer: (B) Deterministic

Question: Which is NOT an encryption arithmetic operation?

Options:

(A) Modular multiplication

(B) XOR

(C) Routing update

(D) Exponentiation

Correct Answer: (C) Routing update

Question: One-way functions are important because they are:

Options:

(A) Easily reversible

(B) Hard to invert

(C) Random

(D) Inefficient

Correct Answer: (B) Hard to invert

Question: Cryptanalysis targets:

Options:

(A) Arithmetic weakness

(B) Routing tables

(C) Network speed

(D) Storage

Correct Answer: (A) Arithmetic weakness

Question: Encryption arithmetic operates under:

Options:

(A) Open sets

(B) Finite fields

(C) Infinite sets

(D) Analog values

Correct Answer: (B) Finite fields

Question: Which math concept ensures uniqueness in keys?

Options:

(A) Hashing

(B) Prime factorization

(C) Compression

(D) Switching

Correct Answer: (B) Prime factorization

Question: Public key encryption relies on difficulty of:

Options:

(A) Sorting

(B) Factoring large numbers

(C) Addition

(D) Subtraction

Correct Answer: (B) Factoring large numbers

Question: Arithmetic complexity increases with:

Options:

(A) Smaller keys

(B) Larger key sizes

(C) Lower bandwidth

(D) Fewer users

Correct Answer: (B) Larger key sizes

Question: Symmetric encryption uses:

Options:

(A) Two unrelated keys

(B) One shared secret key

(C) Public key only

(D) Digital certificates

Correct Answer: (B) One shared secret key

Question: Symmetric algorithms are known for:

Options:

(A) High computational cost

(B) Efficiency and speed

(C) Key exchange complexity

(D) Non-repudiation

Correct Answer: (B) Efficiency and speed

Question: AES is preferred because it is:

Options:

(A) Slow

(B) Strong and efficient

(C) Obsolete

(D) Hardware-only

Correct Answer: (B) Strong and efficient

Question: DES is considered insecure due to:

Options:

(A) Large key size

(B) Small key size

(C) High speed

(D) Public key usage

Correct Answer: (B) Small key size

Question: Blowfish is a:

Options:

(A) Stream cipher

(B) Block cipher

(C) Hash function

(D) Routing protocol

Correct Answer: (B) Block cipher

Read More

CN computer networks part 2

26. Bridges operate at which OSI layer?

Options:

(A) Physical

(B) Data Link

(C) Network

(D) Transport

✅ Correct Answer: (B) Data Link

27. Network devices are often:

Options:

(A) Hardware-only

(B) Passive

(C) Software-defined

(D) Analog

✅ Correct Answer: (C) Software-defined

28. TCP/IP model consists of how many layers?

Options:

(A) 2

(B) 3

(C) 5

(D) 4

✅ Correct Answer: (D) 4

29. HTTP belongs to which TCP/IP layer?

Options:

(A) Transport

(B) Application

(C) Internet

(D) Network Interface

✅ Correct Answer: (B) Application

30. Which protocol is connection-oriented?

Options:

(A) UDP

(B) IP

(C) TCP

(D) ARP

✅ Correct Answer: (C) TCP

31. SMTP is best used for:

Options:

(A) File transfer

(B) Email

(C) Real-time streaming

(D) Web browsing

✅ Correct Answer: (B) Email

32. ICMP is mainly used for:

Options:

(A) Encryption

(B) Error reporting

(C) Address assignment

(D) MAC to IP

✅ Correct Answer: (B) Error reporting

33. ARP maps:

Options:

(A) IP to MAC

(B) MAC to IP

(C) Internet to Domain

(D) Domain to IP

✅ Correct Answer: (A) IP to MAC

34. Internet between autonomous systems uses:

Options:

(A) RIP

(B) OSPF

(C) BGP

(D) EIGRP

✅ Correct Answer: (C) BGP

35. TCP congestion control improves:

Options:

(A) Packet size

(B) Network efficiency

(C) Address space

(D) Encryption

✅ Correct Answer: (B) Network efficiency

36. TCP/IP architecture is:

Options:

(A) Centralized

(B) Layer-strict

(C) Decentralized

(D) Hardware-dependent

✅ Correct Answer: (C) Decentralized

37. IPv4 corresponds to which OSI layer?

Options:

(A) Transport

(B) Data Link

(C) Network

(D) Physical

✅ Correct Answer: (C) Network

38. TTL field prevents:

Options:

(A) Fragmentation

(B) Encryption

(C) Infinite routing loops

(D) Encryption errors

✅ Correct Answer: (C) Infinite routing loops

39. IPv4 header size ranges between:

Options:

(A) 10–20 bytes

(B) 20–60 bytes

(C) 40–80 bytes

(D) Fixed 32 bytes

✅ Correct Answer: (B) 20–60 bytes

40. Fragment offset is used for:

Options:

(A) Error checking

(B) Reassembly

(C) Routing

(D) Address translation

✅ Correct Answer: (B) Reassembly

41. Protocol field identifies:

Options:

(A) Source host

(B) Destination host

(C) Encapsulated transport protocol

(D) Fragment size

✅ Correct Answer: (C) Encapsulated transport protocol

42. IPv4 checksum covers:

Options:

(A) Payload only

(B) Header only

(C) Entire packet

(D) Source address only

✅ Correct Answer: (B) Header only

43. Identification field is used during:

Options:

(A) Routing

(B) Fragmentation

(C) Encryption

(D) Addressing

✅ Correct Answer: (B) Fragmentation

44. IPv4 provides:

Options:

(A) Guaranteed delivery

(B) Best-effort delivery

(C) Encrypted delivery

(D) Error-free delivery

✅ Correct Answer: (B) Best-effort delivery

45. Which is NOT an IPv4 limitation?

Options:

(A) Small address space

(B) No built-in security

(C) Large header size

(D) Fragmentation overhead

✅ Correct Answer: (C) Large header size

46. IPv4 address length is:

Options:

(A) 16 bits

(B) 32 bits

(C) 64 bits

(D) 128 bits

✅ Correct Answer: (B) 32 bits

47. CIDR stands for:

Options:

(A) Classless IP Data Routing

(B) Classless Inter-Domain Routing

(C) Common Internal Data Routing

(D) Classless Internal Data Routing

✅ Correct Answer: (B) Classless Inter-Domain Routing

48. Class C address range is:

Options:

(A) 1–126

(B) 128–191

(C) 192–223

(D) 224–239

✅ Correct Answer: (C) 192–223

49. NAT mainly improves:

Options:

(A) Bandwidth

(B) Address efficiency

(C) Encryption

(D) Latency

✅ Correct Answer: (B) Address efficiency

50. NAT is used to:

Options:

(A) Increase speed

(B) Encrypt traffic

(C) Translate private to public IPs

(D) Assign MAC addresses

✅ Correct Answer: (C) Translate private to public IPs

Read More

CN : computer networks part 1

51. Supernetting is also known as:

Options:

(A) Subnet masking

(B) CIDR aggregation

(C) Fragmentation

(D) Broadcasting

✅ Correct Answer: (B) CIDR aggregation

52. Private IP addresses are defined in:

Options:

(A) RFC 1918

(B) RFC 791

(C) RFC 2460

(D) RFC 1122

✅ Correct Answer: (A) RFC 1918

53. IPv6 address length is:

Options:

(A) 64 bits

(B) 96 bits

(C) 128 bits

(D) 256 bits

✅ Correct Answer: (C) 128 bits

54. Class D addresses are used for:

Options:

(A) Multicast

(B) Broadcast

(C) Unicast

(D) Experimental

✅ Correct Answer: (A) Multicast

55. CIA triad stands for:

Options:

(A) Control, Integrity, Authentication

(B) Confidentiality, Integrity, Availability

(C) Communication, Internet, Access

(D) Cryptography, Integrity, Access

✅ Correct Answer: (B) Confidentiality, Integrity, Availability

56. VPNs primarily provide:

Options:

(A) Speed

(B) Secure tunneling

(C) Routing

(D) Addressing

✅ Correct Answer: (B) Secure tunneling

57. IDS differs from IPS because IDS:

Options:

(A) Blocks traffic

(B) Detects only

(C) Encrypts packets

(D) Routes packets

✅ Correct Answer: (B) Detects only

58. HTTPS uses which security protocol:

Options:

(A) SSL/TLS

(B) IPsec

(C) SSH

(D) S/MIME

✅ Correct Answer: (A) SSL/TLS

59. Firewall rules are based on:

Options:

(A) Physical location

(B) Traffic filtering policies

(C) Application code

(D) Hardware design

✅ Correct Answer: (B) Traffic filtering policies

60. SSH is used for:

Options:

(A) File transfer

(B) Secure remote login

(C) Video streaming

(D) Routing

✅ Correct Answer: (B) Secure remote login

61. Which is an example of network application?

Options:

(A) Compiler

(B) Email

(C) BIOS

(D) Cache memory

✅ Correct Answer: (B) Email

62. Encryption ensures:

Options:

(A) Availability

(B) Confidentiality

(C) Routing

(D) Authentication only

✅ Correct Answer: (B) Confidentiality

63. Network security is critical mainly for:

Options:

(A) Home use

(B) Gaming only

(C) Enterprise and government systems

(D) Entertainment systems

✅ Correct Answer: (C) Enterprise and government systems

64. MPLS improves:

Options:

(A) Packet loss

(B) QoS and traffic engineering

(C) Encryption

(D) Addressing

✅ Correct Answer: (B) QoS and traffic engineering

65. Optical fiber supports:

Options:

(A) Low bandwidth

(B) Electrical signaling

(C) High-speed data transmission

(D) Analog signals only

✅ Correct Answer: (C) High-speed data transmission

66. 5G networks mainly enhance:

Options:

(A) Latency and speed

(B) Addressing

(C) Encryption

(D) Switching

✅ Correct Answer: (A) Latency and speed

67. SDN separates:

Options:

(A) Routers and software

(B) Control and data plane

(C) LAN and WAN

(D) IP and MAC

✅ Correct Answer: (B) Control and data plane

68. NFV replaces:

Options:

(A) Routers

(B) Switches

(C) Dedicated hardware appliances

(D) Cables

✅ Correct Answer: (C) Dedicated hardware appliances

69. IoT applications require:

Options:

(A) High power

(B) Low latency and scalability

(C) Large screens

(D) Wired connections only

✅ Correct Answer: (B) Low latency and scalability

70. Token Ring heavily relies on:

Options:

(A) Token Ring

(B) High-speed networks

(C) Dial-up

(D) Analog links

✅ Correct Answer: (A) Token Ring

71. Video conferencing is sensitive to:

Options:

(A) Address space

(B) Packet loss

(C) MAC addressing

(D) Fragmentation

✅ Correct Answer: (B) Packet loss

72. Digital transformation is driven mainly by:

Options:

(A) Manual systems

(B) High-speed networking technologies

(C) Paper-based processes

(D) Standalone computers

✅ Correct Answer: (B) High-speed networking technologies

Read More

**The Wait That Never Ended**

 In a small village, there lived a boy named Aarav. His whole world was his mother, Sarla. His father had passed away when he was very young, and his mother worked in other people’s houses to educate him.

Aarav would always say,
“Mom, one day I will become a great man… and I will keep you like a queen.”

His mother would smile and reply,
“I only want one thing—that you always stay close to me.”

Time passed, and Aarav moved to the city. He got a good job, earned money, made new friends… and slowly, he started answering his mother’s calls less and less.

One day, with a trembling voice, his mother said,
“Son, will you come home this festival?”

Aarav replied in a hurry,
“Mom, I’m very busy… next time, for sure.”

That “next time” never came.

A few months later, late at night, he received a phone call—
“Your mother is very sick… come quickly.”

Aarav rushed back to the village, but he was too late.

Near his mother’s bedside was an old box. Inside it were his childhood photographs, the receipt of his first school fee, and a letter—

“Son,
I know you have become a very successful man.
But always remember one thing—
Greatness is not sitting on a high chair,
Greatness is never leaving your mother alone.

I am not angry with you…
Because even if a mother gets upset,
She never stops loving.

—Mom”

Aarav broke down in tears.

That day, even after gaining everything in life,
he had lost the most precious thing he ever had.

Moral:

Sometimes, while trying to win the world for the people we love,

we end up losing those very people in their wait.😔

Read More

Mission 100 Trees Planting

Planting 100 trees is a great positive step, but it won’t stop global warming by itself. Here’s the real impact:

On average, one healthy tree absorbs about 20–25 kg of CO₂ per year once it grows. 

So, 100 trees could absorb roughly:

100 \times 22 \text{ kg} \approx 2,200 \text{ kg CO₂/year}

That equals about 2.2 metric tons of CO₂ per year.

100 \times 22\text{ kg CO_2/year} \approx 2200\text{ kg CO_2/year}

To understand the scale:

2.2 tons of CO₂ is roughly similar to emissions from:

Driving a car for about 8,000–10,000 km

Electricity use of a small home for several months

Over 20–30 years, your 100 trees could remove 40–60 tons of CO₂ if they survive and grow well.

Beyond carbon, trees also:

Cool local temperatures

Improve air quality

Increase rainfall support

Reduce soil erosion

Provide shade and wildlife habitat

The biggest impact comes when many people plant trees together. If 1,000 people each planted 100 trees, that would mean 100,000 trees — a much larger climate effect.

For a hot city like Ahmedabad, planting shade trees can also reduce local heat and reduce AC use during summer.

Read More

Hot summer 🔥

Read More

1 st may : Gujarat establishment day

Read More