Networks in their simplest form are things connected to each other. This can be something as generic as two friends speaking with one another or as complex as multiple devices exchanging information. In computing, networks can include everything from your laptop and smartphone to traffic signals and security cameras.
The internet can be described as one huge network that includes many smaller networks within. These smaller networks are called private networks, where networks that are connecting these smaller networks are called public networks. (The Internet)
In order for these parties (devices) to communicate within these networks, they must have labels of some sort to help identify who they are. (Why would you talk to anyone without knowing their name, right?) People are usually identified by our name or our fingerprint. We can change our names but we can't change our fingerprints. This is similar to network devices. Devices have two means of identification:
IP Address
Media Access Control (MAC) Address
IP Address
IP Addresses or Internet Protocol Addresses can be used to identify network hosts for a designated period of time, where that IP address can then be given to another device without it changing.
An IP address is divided into four sets of numbers called Octets. These octets summarize to be the IP address of the host/device on the network. This is calculated through a process called subnetting.
IP addresses follow a set of standards known as protocols. These protocols manage the network traffic between devices; forcing hosts to communicate in the same language/format. I'll touch more on this later down the line.
A public IP address is used to identify a device on the internet. A private IP address is used to identify a device amongst other devices.
Example:
Device Name IP Address IP Address Type
DESKTOP-KJE57FD 192.168.1.77 Private
DESKTOP-KJE57FD 86.157.52.21 Public
CMNatic-PC 192.168.1.74 Private
CMNatic-PC 86.157.52.21 Public
Two devices on the same private network can use their private IP addresses to communicate with each other, However, any data that's being sent from these devices to the internet will be tagged with their public IP addresses. Public IP addresses are purchased through your ISP (Internet Service Provider).
Cisco estimates that 50 BILLION devices will be connected on the internet by 2022. This makes it extremely difficult to get a public IP address that isn't already in use. To solve this problem, we use different versions of the IP addressing scheme known as IPV4 & IPV6.
IPV4 uses a numbering system of 2^32 IP addresses. (4.29 billion) IPV6 uses a system of 2^128 IP addresses. (340 trillion +). Take a look at some examples of both below. Do you see the difference?
MAC ADDRESS
All network devices have a physical network interface, which is usually a network adapter or a microchip on the motherboard. The factory that produces these devices assign a unique address to each called a Media Access Control (MAC) address. This address is a 12 character hexadecimal number split into pairs and separated by a colon. The first six characters represent the company that produced the interface, the last six are unique to the device.
Here's the funny thing, these MAC addresses can be spoofed or faked in a process known as "spoofing". This occurs when a network device pretends to be another using its MAC address. This can often break poorly implemented security protocols that assume every device on the network is trustworthy. Let's say a firewall is implemented to only allow network traffic from a certain MAC address. If this address was spoofed by another device, the firewall would allow all traffic from that device into the network.
Those are some of the basic ideas behind computer networking. I plan on blogging a bit more this year so stay tuned!
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