11.1.1 Networking Basics

Learn the basics behind computer networks.

The Internet is simply the collection of all computer devices that are sharing device with one another.

Networking Components

• Node: the devices that will be communicating (e.g. desktop/laptop/mobile phone, gaming console, IoT device, server)
• Network-Medium: the connection method used to link the nodes together
• Network Interface: the device that translates the digital data to the analog form the medium uses (e.g. binary to light pulses for fiber optic cabling)
• Network Protocols: the set of communication standards used by every device on the network

Network Addressing

The identification standards used to differentiate between the different devices and subnets on a network, equivalent to the physical addressing system used by nations. A device's IP address is equivalent to the address of a building.

An IP address has two parts, the Network ID (equivalent to the street name) and the Host ID (the building number). There are two different versions of IP addresses, IPv4 and IPv6.

IPv4

192.168.1.50 (decimal view) 11000000 | 10101000 | 00000001 | 10010110 (binary view)

Each number is called an octet because it consists of a byte (8 bits) The first three octets represent the Network ID, meaning that every device's IP address on this network WILL begin with 192.168.1. The last octet represents the Host ID, which is the unique identifier given to every node on the network.

Depending on the size of the network, the first three octets denote the Network ID. For larger networks it may be only the first two, and for really large networks it may be just the first octet. This creates space for many more nodes to be connected to the network.

Subnet Mask

The subnet mask is responsible for splitting the raw IPv4 address into it's Network ID and Host ID.

192.168.1.14 (Raw IPv4 Address) 255.255.0.0 (Subnet Mask)

In binary terms, ANDing the subnet mask with the raw address will give you the Network ID, and ANDing the inverse of the subnet mask will give you the Host ID. The subnet mask defines the IP range for the subnet, which is a smaller portion of a larger network. The subnet could be thought of as a street in a neighborhood, where the neighborhood is the larger network.

Two devices can connect easily if they both have unique IP addresses. If they're on the same subnet, communication is relatively easy. If not, communications have to pass through the default gateway of the subnet to access outside networks.

Networking makes device management simpler, since instead of performing operations on devices manually, you can perform one operation on the group as a whole.

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