Netwhat 🐟 🐲

This project is an introduction to network problematics.

Netwhat will allow you to discover the network and to learn about its inner workings. This will allow you to understand how some things work that you already use in your everyday life.

Before you start, study the section Basic Concepts. When you're ready, run the program built in python:

Run the Quiz

🔔 Requirements: Python 3.7.3

pip install colorama
python3 nwtwhat_app.py

01. If an Ethernet port on a router were assigned an IP address of 21.121.54.71/15, which host address would be able to communicate with it? 

 (a) 166.121.177.233 
 (b) 95.199.103.46 
 (c) 21.121.241.69 
 (d) 244.28.220.100 
 (e) 198.58.153.142 
 (f) 79.46.141.190 
 (g) 167.232.175.162


Your Answer: c
[ OK ]

You got 1/20 Correct
Time taken: 00:00:20

Basic Concepts 📚

0️⃣1️⃣ What is an IP address?

It is a network address for our computers and the internet knows where to send informations and data. Every website (42, Microsoft, Apple, etc.) has a unique IP address, but it goes by its name instead (42, Microsoft, Apple, etc.) But without IP addresses you couldn't connect with them and they couldn't share information with you. IP Addres is composed of: [ network ] [ host ] IP Addres Example:

66.171.248.170

0️⃣2️⃣ What is a Netmask?

A Netmask is a 32-bit "mask" used to divide an IP address into subnets and specify the network's available hosts.

0️⃣3️⃣ What is the subnet of an IP with Netmask

It is called a subnet mask because it is used to identify network address of an IP address by perfoming a bitwise AND operation on the netmask.

<network> <subnet> <host>

0️⃣4️⃣ What is the broadcast address of a subnet?

Highest IP address in a subnet or network, used as the destination IP address for broadcast messages.

0️⃣5️⃣ What are the different ways to represent an ip address with the Netmask?

Netmask is a 32-bit "mask" used to divide an IP address into subnets and specify the network's available hosts.

Example:

255.255.255.0
# Applied to
129.144.41.101
# The result is the IPv4 address of 
129.144.41.0

129.144.41.101 
# Applied to
255.255.255.0
# The result is:
129.144.41.0

In binary form, the operation is:

  10000001.10010000.00101001.01100101  # IPv4 address [AND] Netmask
# |||||||| |||||||| |||||||| ||||||||
  11111111.11111111.11111111.00000000 
# |||||||| |||||||| |||||||| ||||||||
# vvvvvvvv vvvvvvvv vvvvvvvv vvvvvvvv
  10000001.10010000.00101001.00000000  # 129.144.41.0/24

0️⃣6️⃣ What are the differences between public and private IPs?

Public Ip can to be static or dynamic.

• A static address is unchanged and is often for hosting websites, server.
• A dynamic address are chasen from a "pool" of available addresses and will be changed each time user connects.

0️⃣7️⃣ What is a class of IP addresses?

IP address in class A, class B and class C.

Class	Starting IP address	Ending Ip Address	Number of Host
A	10.0.0.0	10.255.255.255	16,777,216
B	172.16.0.0	172.31.255.255	1,048,576
C	192.168.0.0	192.168.255.255	65,536

0️⃣8️⃣ What is TCP?

TCP (Transmision Control Protocol) Main protocols of the internet protol suite.

• Keeps track of lost packages, makes sure that lost packages are re-sent
• Addes sequesce numbers to packets and reorders any packets that arrive in thenworng order.
• Slower, because of all added additional functionality.
• Requieres more computer resources, because the OS needs to keep track of ongoing communication sessions and manage them on a much deeper level.

0️⃣9️⃣ What is UDP?

• Doesn't keep track of lost packages
• Doesn't care about package arrival order.
• Faster, bacause it lacks any extra features.
• Requieres less computer resources.
• Examples of programs and services that use UPD:
  • DNS
  • IP telephony
  • DHCP
  • Many computer games

Why we use UDP?

Many applications that requiere real-time communication prefer to use UDP, applications that requiere speed and that torerat partial data loss.

🔟 What are the network layers?

In the seven-layer OSI model of computer network, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers.

1️⃣1️⃣ What is the OSI model?

The Open System Interconnection (OSI). It has been developed by ISO - 'International Organization of Standardization'. It is a 7 layer architecture with each layer having specific functionality to perform. All tese 7 layers work collaboratively to transmit the data fr4om one person to another across the globe.

Layer	Kind
Application Layer	software layer
Presentatation layer	software layer
Session Layer	software layer
Transport Layer	Heart of OSI
Network Layer	hardware Layer
Data Link Layer	hardware Layer
Physical layer	hardware Layer

1️⃣2️⃣ What is a DHCP server and the DHCP protocol

DHCP server: DHCP (Dynamic Host Confivguration Protocol), is a protocol that provides quick, automatic, and central management for the distribution of IP addresses within a network. DHCP is also used to configure the subnet mask, default gateway and DNS server information on the device.

1️⃣3️⃣ What is a DNS server and the DNS protocol?

Domain Name System (DNS) is the phonebook of internet. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load internet resources.

The Domain Network System (DNS) protocol helps internet users and network devises discover websites using human-readable hostnames, instead of numeric IP addresses.

1️⃣4️⃣ What are the rules to make 2 devices communicate using IP addresses?

1️⃣5️⃣ How does routing work with IP?

• Routing is the process by which data packets move from one node (machine or device) to another on a computer network until the packets reach the final destination.

The header information includes:

• The IP addresses of the source and destination nodes.
• Packet numbers that help reassemble the packets in the correct order whe the packets reach the destination.
• Other useful technical information.

1️⃣6️⃣ What is a default gateway for routing?

It allows devices within one network to send information to devises within another network. If you are requestiong a certain web page, the trafic is first sent to your default gateay before leaving the local network to reach its indended destination.

1️⃣7️⃣ What is a port from an IP point of view and what is it used for when connecting?

In computer networking, a port is a communication endpoint. At the software level, within an operating system, a port is a logical construct that identifies a specific process or a type of network service. Ports are identified for each protocol and address combination by 16-bit unsigned numbers, commonly known as the port number. The most common protocols that use port numbers are the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).

🔈 References :

• How to Find the Broadcast Address
• Introduction to Networking
• IP-Calculator
• How does DNS work?
• What Is an Ethernet Port
• ips addres calculation table by Michael Giraldo @mgiraldo 👦
• training to nwtwhat

👧 🎆 The concepts were extracted from various web resources for educational purposes only.

Netwhat pdf new curriculum

• Download from HERE