IP addresses are numerical labels assigned to devices connected to a computer network that uses the Internet Protocol for communication. They serve two main purposes: identifying the host or network interface and providing the location of the device in the network.

Types of IP Addresses:

1. IPv4:
   • Format: Four sets of numbers separated by periods (e.g., 192.168.1.1).
   • Each number can range from 0 to 255.
   • Total possible addresses: About 4.3 billion.
   • Most commonly used but limited in address space.
2. IPv6:
   • Format: Eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).
   • Designed to replace IPv4 due to the exhaustion of available addresses.
   • Total possible addresses: Approximately 340 undecillion (3.4 x 10^38).

Dynamic vs. Static IP Addresses:

• Dynamic IP Addresses:
  • Assigned by a DHCP (Dynamic Host Configuration Protocol) server.
  • Can change over time, making them suitable for most home networks.
• Static IP Addresses:
  • Manually assigned and do not change.
  • Often used for servers or devices that need a constant address.

Public vs. Private IP Addresses:

• Public IP Addresses:
  • Accessible over the internet.
  • Assigned by your Internet Service Provider (ISP).
• Private IP Addresses:
  • Used within a local network (e.g., home or office).
  • Not routable on the internet (e.g., 192.168.x.x, 10.x.x.x).

How They Work:

When a device connects to a network, it is assigned an IP address, which allows it to send and receive data. Data packets include the source and destination IP addresses, ensuring they reach the correct device.

Address Resolution Protocol (ARP)

• What it Does: ARP is used to map IP addresses to MAC (Media Access Control) addresses on a local network. When a device wants to communicate with another device using its IP address, ARP helps it find the corresponding MAC address, enabling the transmission of data packets.

Subnetting

• Purpose: Subnetting divides a larger network into smaller, manageable sub-networks (subnets). This helps improve network performance and security.
• How it Works: By using a subnet mask, which determines how many bits of the IP address represent the network and how many represent the host, organizations can effectively manage their IP address space.

Network Address Translation (NAT)

• Function: NAT allows multiple devices on a private network to share a single public IP address. This conserves IP addresses and adds a layer of security.