Networking Fundamentals​, Quick Notes – Connectivity Options Part 2

Fiber Optic Card & Cable

Connectivity using Fiber Optic NIC & Fiber Cable

  • Uses optical technology for communication instead of electric signals.
  • No EMI, Near-end Crosstalk (NEXT), or Far-end Crosstalk (FEXT).
  • Suitable for long distances and/or places that has heavy EMI.
  • Optic cables are made of high-quality glass or fiber, covered by durable plastic or PVC.
  • Require high precision for termination at both ends.
  • Optical Network cards & optical cables are expensive compared to normal NIC / twisted pair cables.
  • Optical Fiber Types:
    • Single-Mode Fiber (SMF) for long distances.
    • Multi-Mode Fiber (MMF) for shorter distances.

Single Mode Fiber Optic Cable

Multi Mode Fiber Optic Cable

Fiber Optic Connector

Fiber Optic Network Card

Fiber Optic Cable Tester

Fiber Cable with Connectors

   

Standards

Transmission Standards

100 Mb Ethernet

1000 Mb Ethernet

10 Gb Ethernet

40 Gb Ethernet

100 Gb Ethernet

OM1 (62.5/125)

2000 meters (FX)

275 meters (SX)

33 meters (SR)

Not supported

Not supported

OM2 (50/125)

2000 meters (FX)

550 meters (SX)

82 meters (SR)

Not supported

Not supported

OM3 (50/125)

2000 meters (FX)

550 meters (SX)

300 meters (SR)

100 meters

100 meters

OM4 (50/125)

2000 meters (FX)

1000 meters (SX)

550 meters (SR)

150 meters

150 meters

Standard

Specification

Speed

Media

10BASEFL

IEEE 802.3

10 Mbps

Fiber Optic

100BASE-FX

IEEE 802.3u

100 Mbps

Fiber Optic

1000BASESX

IEEE 802.3z

1 Gbps

Fiber Optic

1000BASELX

IEEE 802.3z

1 Gbps

Fiber Optic

10GBASE-SR

IEEE 802.3ae

10 Gbps

Fiber Optic

10GBASE-SW

IEEE 802.3ae

10 Gbps

Fiber Optic

10GBASE-LX4

IEEE 802.3ae

10 Gbps

Fiber Optic

10GBASE-LR

IEEE 802.3ae

10 Gbps

Fiber Optic

10GBASE-LW

IEEE 802.3ae

10 Gbps

Fiber Optic

10GBASE-ER

IEEE 802.3ae

10 Gbps

Fiber Optic

Hub

An 8 Port Hub, can connect up to 8 devices

  • Operates at Layer 1 (Physical).
  • Is a Multi-port repeater, broadcasts to all ports.
  • Usually available as 4, 5 or 8 port options.
  • Limited to half-duplex communication.
  • Network can be extended by using repeaters, following 5-4-3 rule.
  • Transfer speeds 10 to 100 Mbps.
  • Not suitable for large number of computers.
  • Replaced by Network Switch.

Layer 1: A hub forwards to all other ports, hence not suitable beyond small networks

5-4-3 Rule

An Ethernet segment can be extended using 4 repeaters (which means maximum of 5 segments) and 3 of 5 segments can have devices. This rule applies only to networks that use repeaters (olden days when 10 Mbps / hubs were used).

Repeater

  • Operates at Layer 1.
  • Used for extending networks.
  • Works by amplifying and re-transmitting signals.

Network Bridge

  • Operates at Layer 2.
  • Uses MAC table for forwarding frames.

Switch (a.k.a Network Switch)

A 24 Port Network Switch, with Uplink/Downlink Ports

  • Operates at Layer 2 (Data Link).
  • Suitable for small, medium and/or large networks.
  • Is a Multi-port Bridge.
  • Builds MAC table based on devices connected to it, analyzes frames and forwards to matching MAC address thereby minimizing collisions.
  • UsesStore and forward, cut through, Fragment free or Adaptive switching method
  • Full-duplex communication.
  • Usually has 4, 8, 16, 24, 32 or 48 ports, designed to support transfer speeds 10 to 10000 Mbps.
  • Networks areextended by cascading multiple network switches and/or by using Uplink/Downlink Ports if available (depending on the model).
  • ARP (Address Resolution Protocol), used for resolving IP to MAC Address.
  • Types
    • Unmanaged Switch: Designed to work automatically requiring no technical expertise; suitable for most home & small office networks.
    • Managed Switch: Requires specific technical expertise based on vendor / model.

Layer 2: A switch analyzes and forwards data packet to the matching MAC address

Unmanaged Switch

Managed Switch

Fiber Optic Switch

Typical features:

  • Has serial port, USB and/or web based facilities for administration.
  • Access Control is a security feature that allows only authorized devices to be connected; for example, only administrator authorized computers can be connected by white-listing MAC addresses.
  • Facility to remotely monitor & manage, using the Simple Network Management Protocol.
  • Modify duplex, speed & other settings.
  • VLAN (Virtual LAN) is a feature used for partitioning layer-2 networks, for security purposes and to reduce collisions; VLANs can be created to isolate different departments even if all computers are connected to a single network switch (Or multiple network switches).

Departments isolated through virtual networks, though connected to same switch

  • PoE (Power Over Ethernet) is a facility that supplies electrical power through network cables (UTP) for end devices such as Network Cameras, IP Phones, Wireless Access Points, etc. eliminating the need forseparate power adapters for end devices (Approx. 57 Volts/100 Watts depending on the model).

Network Switch with PoE facility providing data & power to a CCTV Camera & a VoIP Phone 

Network Switch Worksheet

Vendor

   

Model

   

Desktop / Rack Mount

   

Managed / Unmanaged

   

No. of Ports (UTP/STP)

   

No. of Ports (Optical)

   

No. of Ports (PoE)

   

Console Port (Yes / No)

   

Web Interface (Yes / No)

   

VLAN (Yes / No)

   

Standard Compliance

IEEE 802.3

   

IEEE 802.3u

   

IEEE 802.3ab

   

IEEE 802.3x

   

IEEE 802.3z

   

IEEE 802.1q

   

IEEE 802.1p

   

IEEE 802.3ad

   

IEEE 802.3az

   

IEEE 802.3w

   

IEEE 802.1x

   

IP addresses are resolved to MAC addresses, for computers to communicate within a network. Resolved MAC addresses are stored in respective computer’s ARP cache and used for future communication.

Computers connected to a network switch

ARP is a command line utility to view and manage ARP cache.

  • View ARP Cache (Resolved MAC Addresses):
    • CMD > arp -a

Output listing ARP cache, listing IP to MAC Address mapping

  • View ARP Cache:
    • CMD > netsh interface ipv4 show neighbors

Output listing ARP Cache

Note: If the destination host is present on a remote network, MAC address of the gateway will be listed.

  • Clear ARP Cache:

CMD > netsh -d

Quiz 03

1. IEEE standard related to Ethernet ________________.

A. IEEE 802.11 B. IEEE 803.21 C. IEEE 802.3 D. IEEE 802.6

2. IEEE standard related to Bluetooth:

A. IEEE 802.3 B. IEEE 802.12 C. IEEE 802.14 D. IEEE 802.15

3. Which network topology allows computers to be connected to a centralized device?

A. Bus B. Star C. AD-HOC D. Mesh

4. Components used in Bus topology:

A. T-Connector B. BNC Connector C. Co-Axial Cable D. All of the above

5. Components used in Star topology:

A. RJ-45 B. Twisted-pair cable C. Switch D. All of the above

6. _____ is used for amplifying and re-transmitting weak signals.

A. Access Point B. Bridge C. Repeater D. All of the above

7. Advantage of a network switch over a hub:

A. Filters Frames B. Operates at Layer 2 C. Reduces Collision D. All of the above

8. In 10base2 ’10’ refers to:

A. 10 Meters B. 10 Mbps C. 10 Mbps D. Both B & C

9. In 10base2 ‘base’ refers to:

A. Broadband B. Baseband C. Narrowband D. Wideband

10. In 10base2 ‘2’ refers to:

A. 200 Meters B. 200 Mbps C. 2 Mbps D. 200 Feet

11. 10Base2 is also known as:

A. Broadband B. Thinnet C. Thicknet D. Baseband

12. 10Base5 is also known as:

A. Broadband B. Thinnet C. Thicknet D. Baseband

13. Acronym – UTP.

A. Ultimate Twisted Pair B. Unwinded Twisted Pair
C. Unshielded Twisted Pair D. Unlimited Twisted Pair

14. Speed of Ethernet:

A. 10 Mbps B. 100 Mbps C. 1000 Mbps D. 10000 Mbps

15. Speed of Fast Ethernet:

A. 10 Mbps B. 100 Mbps C. 1000 Mbps D. 10000 Mbps

16. In 100baseT ‘T’ refers to:

A. Twisted-Pair B. Telecommunication C. Thin-Pair D. Tele-Pair

17. Category of UTP that support speeds greater than 100 Mbps:

A. Cat 1 B. Cat 2 C. Cat 3 D. Cat 5

18. Category of UTP that support speeds greater than 1000 Mbps:

A. Cat 3 B. Cat 5e C. Cat 6 D. Both B & C

19. Category of UTP used in Telephone lines:

A. Cat 1 B. Cat 2 C. Cat 3 D. Cat T

20. Maximum distance supported by UTP _____.

A. 100 Feet B. 1000 Feet C. 100 Meters D. 10 Meters

21. IEEE 802.3 Specification corresponds to _____ standard.

A. 10BASE2 B. 100BASE-TX C. 1000BASE-T D. 1000BASESX

22. Type of cable that uses light as the media for transmitting signals:

A. Co-Axial B. UTP C. STP D. Fiber-optic

23. Type of cable that is not susceptible to EMI:

A. Co-Axial B. UTP C. STP D. Fiber-optic

24. Type of material used for protecting cables against fire:

A. PVC B. Plenum C. STP D. UTP

25. Type of cable preferred for connecting dissimilar devices:

A. Single-mode fiber B. Straight through C. Cross over D. PVC Coated

26. Type of cable preferred for connecting similar devices:

A. Single-mode fiber B. Straight through C. Cross over D. PVC Coated

27. Type of NIC for use in desktop computers.

A. PCI B. PCIe C. USB D. All of the above

28. Type of NIC for use in laptop computers.

A. PCI B. CardBus C. ExpressCard D. ISA

29. _____ is a unique hardware address assigned to an NIC.

A. MAC B. IP C. IPX D. TCP

30. MAC addresses are _____ addresses.

A. 16-bit B. 32-bit C. 48-bit D. 64-bit

31. Example of a valid MAC address:

A. 00-B0-D0-1D-F5-5B
B. 192.168.2.5
C. 00-B0-D000-B0-D000-B0-D000-B0-D0
D. server05

32. Connectors for Ethernet card _____.

A. RJ-11 B. RJ-58 C. RJ-45 D. RJ-E

33. Connectors for telephones _____.

A. RJ-11 B. RJ-58 C. RJ-45 D. RJ-E

34. _____ is a special chip that allows loading of an operating system over a network.

A. WOL B. Boot ROM C. MAC ROM D. RIS

35. Procedure through which devices choose common transmission parameters such as speed; duplex mode and flow control:

A. Auto-negotiation B. Auto-duplex C. Auto-connection D. Auto-speed

36. Layer 1 device _____.

A. Hub B. Bridge C. Switch D. Router

37. Layer 2 devices _____.

A. Hub B. Bridge C. Switch D. Router

38. Layer 3 devices _____.

A. Hub B. Bridge C. Switch D. Router

39. _____ is a multi-port repeater.

A. Hub B. Bridge C. Switch D. Router

40. _____ is a multi-port bridge.

A. Hub B. Switch C. Router D. Access Point

41. MAC Addresses are also known as _____.

A. Logical Address B. Routing Address C. Network Address D. Physical Address

42. Type of switch that do not require administrative configuration:

A. Managed B. Unmanaged C. Typical D. Custom

43. Acronym – VLAN.

A. Visual LAN B. Virtual LAN C. Vertical LAN D. Viral LAN

44. Device that helps reduce broadcast domains:

A. Hub B. Switch C. Router D. Access Point

45. _____ reduces collisions and improves security.

A. WLAN B. Wi-Fi C. VLAN D. CSMA/CD

46. System that supplies electricity through Ethernet cables:

A. VLAN B. PoE C. WOL D. CSMA/CA

47. Methods used in switching:

A. Store and forward B. Cut through C. Fragment free D. All of the above

48. Device used for creating patch cables:

A. Patch Tool B. Crimping Tool C. Cable Tester D. Loopback Adapter

49. 2-pair Straight-through pin / cable configuration:

A. 1-2; 2-1; 3-6; 6-3 B. 1-3; 3-1; 2-6; 6-2
C. 1-1; 2-2; 3-3; 6-6 D. 1-6; 6-1; 2-3; 3-2

50. 2-pair Cross-over pin / cable configuration:

A. 1-2; 2-1; 3-6; 6-3 B. 1-3; 3-1; 2-6; 6-2
C. 1-1; 2-2; 3-3; 6-6 D. 1-6; 6-1; 2-3; 3-2

51. Command-line utility for viewing MAC address:

A. IPCONFIG B. GETMAC C. VIEWMAC D. HOSTNAME

52. MAC addresses are usually displayed in _____ format.

A. ASCII B. Hexadecimal C. Numeric D. Encrypted

53. Utility for viewing or modifying settings of network interface cards:

A. GETMAC B. Device Manager C. Disk Manager D. Network Manager

54. Correct syntax for viewing MAC address with manufacturer / model details:

A. GETMAC B. GETMAC /v C. IPCONFIG /m D. IPCONFIG /L

55. _____ resolves IP addresses to MAC addresses.

A. ARP B. DHCP C. DNS D. WINS

56. Command to view ARP Cache

A. GETMAC B. IPCONFIG C. ARP D. PING

57. _____ is used for network management & monitoring.

A. SMTP B. SNMP C. POP3 D. FTP

58. Type of Connectors used for Fiber-Optic NIC.

A. RJ-11 B. RJ-45 C. MT-RJ D. BNC

59. Acronym – NEXT (Context: Signaling):

A. Null End Crosstalk B. Null Ethernet Crosstalk
C. Near End Crosstalk D. All of the above

60. Acronym – FEXT (Context: Signaling):

A. Field End Crosstalk B. Far End Crosstalk
C. Federation End Cross Talk D. Far Ethernet Crosstalk

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