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Introduction

Computer networks are the foundation of modern communication. From home Wi-Fi to global internet backbones, networks connect devices, people, and data worldwide. In this post, we answer 58 frequently asked questions (FAQs) about networks, LAN, WAN, Ethernet, cables, and related technologies in a clear and structured way.

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FAQs on Computer Networks

1. What is this network?

A network is a collection of interconnected devices (computers, servers, routers) that communicate and share resources.

2. What are the 10 types of networks?

1. LAN (Local Area Network)
2. WAN (Wide Area Network)
3. MAN (Metropolitan Area Network)
4. WLAN (Wireless LAN)
5. PAN (Personal Area Network)
6. VPN (Virtual Private Network)
7. SAN (Storage Area Network)
8. CAN (Campus Area Network)
9. VLAN (Virtual LAN)
10. Enterprise Private Network

3. What are the 3 types of computer networks?

• LAN
• MAN
• WAN

4. What is LAN, WAN, and MAN?

• LAN: Small network (home, office).
• MAN: Medium-sized (city-wide).
• WAN: Large-scale (country or global, e.g., Internet).

5. What is WAN, LAN, and VPN?

• WAN: Wide Area Network (Internet).
• LAN: Local network in homes/offices.
• VPN: Virtual network over the internet providing privacy.

6. What is WAN IP and LAN IP?

• WAN IP: Public IP visible on the internet.
• LAN IP: Private IP used inside local networks.

7. What is WAN, LAN, and VLAN?

• LAN: Local Area Network.
• WAN: Wide Area Network.
• VLAN: Virtual LAN created by segmenting a physical LAN.

8. What is PAN and WAN?

• PAN: Personal Area Network (Bluetooth, USB).
• WAN: Wide Area Network (Internet).

9. What is VLAN vs WLAN?

• VLAN: Virtual LAN created with switches.
• WLAN: Wireless LAN (Wi-Fi).

10. What is WAN vs Ethernet?

• WAN: A type of network covering large areas.
• Ethernet: A technology used for wired LANs.

11. Is Wi-Fi a LAN or WAN?

Wi-Fi is a LAN technology (Wireless LAN).

12. Which cable is used in WAN?

Mostly fiber optic cables or leased lines.

13. What is the difference between RJ45 and WAN?

• RJ45: A connector for Ethernet cables.
• WAN: A large area network.

14. What is RJ45 vs Cat6?

• RJ45: Connector.
• Cat6: Ethernet cable type (supports higher speeds).

15. Can LAN exist without WAN?

Yes, LANs can work independently without internet access.

16. What is the difference between T568A, T568B, and RJ45?

• T568A & T568B: Wiring standards.
• RJ45: Connector that uses these standards.

17. Which Ethernet wires carry power?

In PoE (Power over Ethernet), pairs 1-2 and 3-6 or 4-5 and 7-8 carry power.

18. What are keystone jacks?

Modular jacks mounted on wall plates for Ethernet connections.

19. What is the maximum length of an Ethernet cable?

100 meters (328 feet).

20. How to boost Ethernet signal?

Use Ethernet switches, repeaters, or fiber extenders.

21. What is standard Ethernet?

Ethernet defined by IEEE 802.3 standards.

22. Which topology is used in Ethernet?

Star topology.

23. What is the difference between switch and bridge?

• Switch: Connects multiple devices in a LAN.
• Bridge: Connects two LAN segments.

24. What are the three standards in Ethernet?

1. 10 Mbps (Ethernet)
2. 100 Mbps (Fast Ethernet)
3. 1 Gbps (Gigabit Ethernet)

25. What are the 7 structured parts of an Ethernet frame?

1. Preamble
2. Start Frame Delimiter
3. Destination MAC
4. Source MAC
5. EtherType/Length
6. Data Payload
7. Frame Check Sequence

26. What is the purpose of Ethernet?

To enable wired communication between devices in a LAN.

27. What are common Ethernet problems?

• Loose connections
• Cable damage
• Collisions
• Network congestion

28. What are the disadvantages of using Ethernet?

• Limited mobility
• Cable clutter
• Fixed length restrictions

29. Why Ethernet and not Wi-Fi?

Ethernet is faster, more reliable, and secure than Wi-Fi.

30. Are Ethernet ports common?

Yes, found in PCs, routers, switches, and modems.

31. How many connections are there in Ethernet?

Ethernet uses 8 wires (4 pairs).

32. How to check if an Ethernet port is connected?

Check LED lights on the port or run ping command.

33. Which port is used for Ethernet?

RJ45 port.

34. Which wires are used in Ethernet?

Twisted pair (Cat5, Cat6, Cat7).

35. What is a LAN outlet?

A wall socket for Ethernet cables.

36. What are RJ45 ports?

8-pin connectors for Ethernet cables.

37. Why is it called RJ45?

RJ = Registered Jack, 45 = Specification number.

38. How many pins are there in RJ45?

8 pins.

39. Why is it called RJ11?

Registered Jack standard #11, used for telephones.

40. Why is it called coaxial cable?

Because the inner conductor and shield share the same axis.

41. Is RJ45 analog or digital?

RJ45 is digital.

42. Is DSL cable RJ11 or RJ12?

DSL typically uses RJ11.

43. Which cable is used in DSL?

Twisted pair telephone cable.

44. Is telephone wire RJ45?

No, telephone wire uses RJ11.

45. How many wires are there in RJ12?

6 wires (3 pairs).

46. What is the real name of RJ45?

8P8C (8 Position, 8 Contact) connector.

47. What is a 6-pin RJ connector called?

RJ12.

48. What is smaller than RJ45?

RJ11 (telephone connector).

49. What is called a phone cord?

Cable used with RJ11 connectors.

50. What does UTP mean?

Unshielded Twisted Pair.

51. Why is RJ45 called 45?

Because it follows specification #45.

52. What is Cat5 cable?

Ethernet cable supporting speeds up to 100 Mbps.

53. How many pairs are there in RJ45?

4 pairs (8 wires).

54. What are keystone jacks?

Modular connectors used in patch panels and wall outlets.

55. What is PAN, LAN, MAN, WAN?

• PAN: Personal Area Network
• LAN: Local Area Network
• MAN: Metropolitan Area Network
• WAN: Wide Area Network

56. What is mesh topology?

Every device connects to every other device, providing redundancy.

57. What is a server?

A powerful computer that provides services, data, or resources to clients.

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