# What is Networking?

## What is the Internet?

The first iteration of the Internet was within the <mark style="color:yellow;">ARPANET project in the late 1960s</mark>. This project was funded by the United States Defence Department and was the first documented network in action. However, it wasn't until <mark style="color:yellow;">1989 that the Internet was invented by Tim Berners-Lee by the creation of the</mark> [<mark style="color:yellow;">WWW</mark>](#user-content-fn-1)[^1]. It wasn't until this point that the Internet started to be used as a repository for storing and sharing information.

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## Identifying devices on a network

Two types of networks, public and private networks

Two means of identification, an [<mark style="color:green;">IP</mark>](#user-content-fn-2)[^2] address and a [<mark style="color:green;">MAC</mark>](#user-content-fn-3)[^3] address.

### IP Addresses

An IP address (or Internet Protocol) address can be used as a way of <mark style="color:yellow;">identifying a host on a network for a period of time</mark>, where that IP address can then be associated with another device without the IP address changing.

An IP address is a set of numbers that are divided into <mark style="color:yellow;">four octets</mark>. IP addresses can change from device to device but <mark style="color:yellow;">cannot be active simultaneously more than once within the same network</mark>.

IP Addresses follow a set of standards known as protocols. These protocols are the backbone of networking and force many devices to communicate in the same language. <mark style="color:yellow;">Devices can be on both a private and public network.</mark> Depending on where they are will determine what type of IP address they have: a <mark style="color:yellow;">public or private IP address</mark>.

A public address is used to identify the device on the Internet, whereas a private address is used to identify a device amongst other devices. Public IP addresses are given by your [<mark style="color:green;">ISP</mark>](#user-content-fn-4)[^4] at a monthly fee

Two types of IP addresses, IPv4 and IPv6.

### MAC Addresses

Devices on a network will all have a physical network interface, which is a microchip board found on the device's motherboard. This network interface is assigned a unique address at the factory it was built at, called a MAC address.

The MAC address is a twelve-character hexadecimal number. The <mark style="color:yellow;">first six characters represent the company</mark> that made the network interface, and the <mark style="color:yellow;">last six is a unique number</mark>.

<mark style="color:yellow;">MAC addresses can be faked or 'spoofed'.</mark> This spoofing occurs when a networked device pretends to identify as another using its MAC address. When this occurs, it can often <mark style="color:yellow;">break poorly implemented security designs</mark> that assume that devices talking on a network are trustworthy.

Example: A firewall is configured to allow any communication going to and from the MAC address of the administrator. If a device were to pretend or "spoof" this MAC address, the firewall would now think that it is receiving communication from the administrator when it isn't.

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## Ping

Ping uses [<mark style="color:green;">ICMP</mark>](#user-content-fn-5)[^5] packets to determine the performance of a connection between devices, for example, if the connection exists or is reliable.

{% code overflow="wrap" fullWidth="false" %}

```bash
ping -c 4 192.168.1.254
```

{% endcode %}

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## Answers

### Task 1

> What is the key term for devices that are connected together?\
> Network

### Task 2 <a href="#id-0c37" id="id-0c37"></a>

> Who invented the World Wide Web?\
> Tim Berners-Lee

### Task 3 <a href="#fcfe" id="fcfe"></a>

> What does the term “IP” stand for?\
> Internet Protocol

> What is each section of an IP address called?\
> Octet

> How many sections (in digits) does an IP address have?\
> 4

> What does the term “MAC” stand for?\
> Media Access Control

> Deploy the interactive lab using the “View Site” button and spoof your MAC address to access the site. What is the flag?\
> THM{YOU\_GOT\_ON\_TRYHACKME}

### Task 4 <a href="#id-6a3d" id="id-6a3d"></a>

> What protocol does ping use?\
> ICMP

> What is the syntax to ping 10.10.10.10?\
> `ping 10.10.10.10`

> What flag do you get when you ping 8.8.8.8?\
> THM{I\_PINGED\_THE\_SERVER}

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[^1]: World Wide Web

[^2]: Internet Protocol

[^3]: Media Access Control

[^4]: Internet Service Provider

[^5]: Internet Control Message Protocol