Networking Fundamentals - OSI & TCP/IP

Question 1

What are the layers of OSI Model?

Answer 1

7. Application
8. Presentation
9. Session
10. Transport
11. Network
12. Data Link
13. Physical

Question 2

Explain Physical Layer of OSI Model.

Answer 2

This is the lowest layer and deals with the physical transmission of data, such as electrical signals, light waves, or radio waves.

Question 3

Explain Data Link Layer of OSI Model.

Answer 3

This layer manages the physical connection between two nodes, ensuring that data is transmitted correctly by handling framing, error detection, and flow control.

Question 4

Explain Network Layer of OSI Model.

Answer 4

This layer is responsible for routing data packets between networks and determining the best path for data to travel.

Question 5

Explain Transport Layer of OSI Model.

Answer 5

This layer provides end-to-end data delivery, ensuring reliable and ordered transmission of data segments.

Question 6

Explain Session Layer of OSI Model.

Answer 6

This layer manages the connections between applications, establishing, maintaining, and terminating sessions.

Question 7

Explain Presentation Layer of OSI Model.

Answer 7

This layer handles data formatting, encryption, and decryption, ensuring that data is presented in a format that is understandable to the receiving application.

Question 8

Explain Application Layer of OSI Model.

Answer 8

This is the highest layer and provides network services to applications, such as email, web browsing, and file transfer.

Question 9

In what order is data transmitted using the 7 layers of the OSI Model?

Answer 9

7-6-5-4-3-2-1

Question 10

In what order is data received using the 7 layers of the OSI Model?

Answer 10

1-2-3-4-5-6-7

Question 11

What are the layers of the TCP/IP Model?

Answer 11

4. Application&raquo_space; (Application, Presentation, & Session) in OSI
5. Transport&raquo_space; same in OSI
6. Internet&raquo_space; (Network) in OSI
7. Network Interface&raquo_space; (Physical & Data Link) in OSI

Question 12

Explain Application Layer of TCP/IP Model.

Answer 12

This layer includes the applications that use the network, such as web browsers, email clients, and file transfer programs.

Question 13

Explain Transport Layer of TCP/IP Model.

Answer 13

This layer provides a reliable connection between two applications, ensuring data is delivered in the correct order and without errors. It uses protocols like TCP and UDP.

Question 14

Explain Internet Layer of TCP/IP Model.

Answer 14

This layer focuses on routing data packets across the network, ensuring they reach their destination. It’s responsible for addressing and routing data packets between different networks.

Question 15

Explain Network Interface Layer of TCP/IP Model.

Answer 15

This layer handles the physical transmission of data over the network, including details like how bits are converted to signals. It’s also responsible for managing connections to the network medium.

Question 16

Examples of Protocols in TCP/IP Application Layer?

Answer 16

HTTP/HTTPS (web browsing)
FTP/SFTP (file transfer)
SMTP/POP3/IMAP (email)
DNS (domain name resolution)
Telnet/SSH (remote access)
SNMP (network management)
DHCP (IP address allocation)

Question 17

Examples of Devices/Tools in TCP/IP Application Layer?

Answer 17

Web browsers
Email clients
Network management systems

Question 18

Examples of Protocols in TCP/IP Transport Layer?

Answer 18

TCP (reliable, connection-oriented)
UDP (unreliable, connectionless)

Question 19

Examples of Key Concepts in TCP/IP Transport Layer?

Answer 19

Ports (e.g. 80 for HTTP, 443 for HTTPS, etc)
Segmentation and Reassembly
Flow control and acknowledgements

Question 20

Examples of Protocols in TCP/IP Internet Layer?

Answer 20

IP (IPv4/IPv6 - logical addressing)
ICMP (error reporting - e.g. ping)
ARP (resolves IP to MAC address)
IGMP (manages multicast groups)

Question 21

Examples of Devices in TCP/IP Internet Layer?

Answer 21

Routers
Layer 3 Switches

Question 22

Examples of Technologies/Protocols in TCP/IP Network Interface Layer?

Answer 22

Ethernet
Wi-Fi (802.11)
PPP
Frame Relay
ATM

Question 23

Examples of Devices in TCP/IP Network Interface Layer?

Answer 23

Switches
NICs (Network Interface Cards)
Hubs
Cables & Connectors

Question 24

Summary of Protocol and Devices for each layer of TCP/IP.

Answer 24

Application Layer&raquo_space; Protocol = HTTP, FTP, SMTP, DNS, DHCP&raquo_space; Devices = Browser, Email Client

Transport Layer&raquo_space; Protocol = TCP, UDP&raquo_space; Devices = N/A (Handled in OS)

Internet Layer&raquo_space; Protocol = IP, ICMP, ARP, IGMP&raquo_space; Devices = Routers, L3 Switches

Network Interface Layer&raquo_space; Protocol = Ethernet, Wi-Fi, MAC&raquo_space; Devices = Switches, NICs, Cables

Question 25

What's the difference between a Layer 2 switch ("regular" switch) and a Layer 3 switch?

Answer 25

Layer 2 switch: Uses MAC addresses to forward traffic within the same network/VLAN. No routing. Layer 3 switch: Uses IP addresses to route traffic between VLANs/subnets. Combines switching and routing.