IP Addresses

Network Identifier (Network ID)

The front part of an IP address, used to define what network the nodes are communicating on

Port Forwarding

This is a technique used to route data to private IP addresses using additional ports

Subnet Mask

A 32-bit number that masks an IP address and divides the IP address into network and host addresses

IP Address

A unique string of numbers that identifies each computer that uses the Internet Protocol to communicate over a network

Classless IP Addressing

IP addresses that have a variable amount of network ID and host ID (not limited to have half and half)

Classful IP Addressing

IP addresses used to categorised into classes to identify the network and host IDs

Making of Subnet Mask

Made by setting network bits all to 1s and all host bits to 0s, then a bitwise AND operation is used to identify the network

x.y.z.255

The IP address which is reserved as the broadcast address on a network for sending data simultaneously to all hosts on the network

Host Identifier (Host ID)

The back part of an IP address, used to identify the different nodes on a network

Benefits of NAT

The private IP is hidden from the internet meaning its safer from unauthorised access and the number of public IP addresses that need registering is limited so saves costs and admin work

IPv6

There are not enough IPv4 addresses available so this is used. It uses 128 bits expressed as a string of 32 hexadecimal digits

Private IP addresses

These are IPs that are non-routable across the internet and are reserved for use within LANs or private WANs (these are IP address starting with 10, 172 or 192)

Network Address Translation (NAT)

This is a technique used to assign a private network a registered public IP that can be mapped to the private IP of each of the devices on the network (it allows multiple devices on a network to share the same public IP)

Security Benefit of Subnet Mask

This is that the IP addresses of the host computers on each subnet are masked by the network address so they are invisible to the outside world

DHCP (Dynamic Host Configuration Protocol)

This is used to automatically assign IP addresses to devices when they connect to a network, this allows the same IP address to be used when different devices connect to the network and allows hosts to reconfigure themselves when moving between networks

IPv4 Standard

This uses four groups of 8 bits (octets) and is written in a decimal-dotted notation (10101010.00000000.1111111.010101010101010)

Subnet

When an organisation further divides the number of available hose IDs that they have between individual subnetworks, this reduces data collisions and improves security