13/10/2023
IP Address in a nutshell:
1. What is an IP Address?
IP stands for Internet Protocol. An IP address is a unique numerical label assigned to each device on a computer network.
2. Types of IP Addresses:
- IPv4:
The most common version with addresses like 192.168.1.1.
- IPv6:
A newer version with longer addresses like 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
3. IPv4 Address Format:
Consists of four sets of numbers separated by dots (e.g., 192.168.1.1).
Each set can range from 0 to 255 (8 bits).
4. IPv4 Classes:
- Class A:
Used for large networks, with the first octet reserved for network identification.
Range: 1.0.0.0 to 126.0.0.0.
- Class B:
Suitable for medium-sized networks. First two octets for network ID.
Range: 128.0.0.0 to 191.255.0.0.
- Class C:
Used for small networks, with the first three octets for network ID.
Range: 192.0.0.0 to 223.255.255.0.
- Class D: Reserved for multicast groups.
- Class E: Reserved for experimental purposes.
5. IPv6 Address Format:
Composed of eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).
6. IP Address Types:
- Public IP Address:
Identifies a device on the internet.
Usually provided by your Internet Service Provider (ISP).
- Private IP Address:
Used within a local network (e.g., home or office).
Defined by RFC 1918, with common ranges like 192.168.x.x, 10.x.x.x, and 172.16.x.x.
7. Subnetting:
- Subnet Mask:
A subnet mask defines the network and host portions of an IP address.
Common subnet masks include 255.255.255.0 for a Class C network.
8. CIDR Notation:
Classless Inter-Domain Routing.
Allows specifying network prefixes using a slash notation (e.g., 192.168.1.0/24).
9. Special IP Addresses:
Loopback Address:
127.0.0.1 for IPv4 (localhost).
::1 for IPv6.
10. Broadcast Address:
Used to send data to all devices on a local network (e.g., 192.168.1.255).
11. Default Gateway:
The device that connects your local network to the internet.
Typically ends with .1 (e.g., 192.168.1.1).
12. Reserved Addresses:
Some IP addresses are reserved for special purposes (e.g., 0.0.0.0, 255.255.255.255).
13. IP Address Assignment:
- DHCP (Dynamic Host Configuration Protocol):
Automatically assigns IP addresses to devices on a network.
- Static IP Address:
Manually configured and doesn't change unless you modify it.
- NAT (Network Address Translation):
Allows multiple devices in a local network to share a single public IP address.
14. IP Version Transition:
Transition from IPv4 to IPv6:
Due to IPv4 address exhaustion, IPv6 adoption is increasing.
IPv6 provides a vastly larger address space.
15. Common Private IPv4 Address Ranges:
Class A: 10.0.0.0 to 10.255.255.255
Class B: 172.16.0.0 to 172.31.255.255
Class C: 192.168.0.0 to 192.168.255.255
