Hello Folks,
In this introductory blog, we will cover the answers for the “Networking Concepts” room which is a part of the “Cyber Security 101” learning path. This room covers the basics of networking, including the concepts of the OSI model, TCP/IP model, IP addresses, subnets, routing, and TCP/UDP. This knowledge will help us understand the backbone of computer networks.
You can access the room by clicking here.
Task 1 Introduction
This task will let you know the learning objectives and prerequisites of this room. You can work on it to understand the networking concepts.
Get your notepad ready, and let’s begin.
No Answer Needed
Task 2 OSI Model
This task covers one of the most vital concepts of networking which is OSI Model. It is a 7 layer framework governing the network communication. Read the concepts of it and then we can easily answer the following questions.
Q 2.1- Which layer is responsible for connecting one application to another?
A 2.1- Layer 4
Q 2.2- Which layer is responsible for routing packets to the proper network?
A 2.2- Layer 3
Q 2.3- In the OSI model, which layer is responsible for encoding the application data?
A 2.3- Layer 6
Q 2.4- Which layer is responsible for transferring data between hosts on the same network segment?
A 2.4- Layer 2
Task 3 TCP/IP Model
The TCP/IP model is another real-time communication model that helps individuals to understand network communication. It is the simplified form of the OSI model. Go through the concepts of this and then work on the following questions.
Q 3.1- To which layer does HTTP belong in the TCP/IP model?
A 3.1- Application Layer
Q 3.2- How many layers of the OSI model does the application layer in the TCP/IP model cover?
A 3.2- 3
Task 4 IP Addresses and Subnets
This task will provide us with the in depth knowledge of IP addresses which helps in uniquely identifying every device present on a network. We will explore different types of IP addresses and a very important technique called Network Address Translation (NAT).
Q 4.1- Which of the following IP addresses is not a private IP address?
a) 192.168.250.125 b) 10.20.141.132 c) 49.69.147.197 d) 172.23.182.251
A 4.1- 49.69.147.197
Q 4.2- Which of the following IP addresses is not a valid IP address?
a) 192.168.250.15 b) 192.168.254.17 c) 192.168.305.19 d) 192.168.199.13
A 4.2- 192.168.305.19
Task 5 UDP and TCP
In this task, we will explore the two most important transport layer protocols which are essential for providing end-to-end connectivity. These protocols are Transmission Control Protocol (TCP) which is used for reliable communication and User Datagram Protocol (UDP) which is used for fast data transmission.
Q 5.1- Which protocol requires a three-way handshake?
A 5.1- TCP
Q 5.2- What is the approximate number of port numbers (in thousands)?
A 5.2- 65
Task 6 Encapsulation
Here, we are going to explore the concepts of encapsulation which is a process of concatenating the header and trailer in each layer to the data received from the previous layer. After reading the content, you can answer the following questions.
Q 6.1- On a WiFi, within what will an IP packet be encapsulated?
A 6.1- Frame
Q 6.2- What do you call the UDP data unit that encapsulates the application data?
A 6.2- Datagram
Q 6.3- What do you call the data unit that encapsulates the application data sent over TCP?
A 6.3- Segment
Task 7 Telnet
Telnet is another useful protocol that allows us to connect to the remote open ports and run text commands which can be useful for accessing services like HTTP, SMTP, echo, etc. This can help us gather information about the service versions of protocols running on the target machine.
Q 7.1- Use telnet to connect to the web server on MACHINE_IP. What is the name and version of the HTTP server?
A 7.1- lighttpd/1.4.63
Q 7.2- What flag did you get when you viewed the page?
A 7.2- THM{TELNET_MASTER}
Task 8 Conclusion
Please note and remember all the concepts, network layers, and protocols explained in this room.
No answer needed
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Happy Pentesting!!!
Team CyberiumX