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IP Addressing

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IP Addressing

IP Address is the most Important in IT , IP address gives the way where our ports and protocol know that , where and which address to connect. When we talk about IP Address, there are 2 types of IP Address

IPv4

IPv6

Difference Between IPv4 and IPv6

IPv4 and IPv6 are Internet Protocol versions used for addressing devices on a network. Here’s a crisp comparison:

Feature IPv4 IPv6
Address Format 32-bit numeric (e.g., 192.168.1.1) 128-bit alphanumeric (e.g., 2001:db8::1)
Address Space ~4.3 billion addresses Virtually unlimited (3.4×10³⁸ addresses)
Header Size 20 bytes 40 bytes
Configuration Manual or DHCP Auto-configuration (stateless address)
Security Optional (IPsec support) Built-in IPsec
Routing Less efficient More efficient (hierarchical addressing)
Broadcast Supported Replaced by multicast
Adoption Widely used Gradually being adopted

Key Takeaway: IPv4 is nearing exhaustion, while IPv6 is the future of scalable and secure networking.

In IPv4, IP addresses are divided into classes based on the first few bits of the address. This classification helps allocate IP ranges for different purposes.

IPv4 Address Classes

Class Range First Octet Purpose Subnet Mask
A 0.0.0.0 - 127.255.255.255 0-127 Large networks (e.g., ISPs, large orgs) 255.0.0.0 (default)
B 128.0.0.0 - 191.255.255.255 128-191 Medium-sized networks 255.255.0.0
C 192.0.0.0 - 223.255.255.255 192-223 Small networks (e.g., small businesses) 255.255.255.0
D 224.0.0.0 - 239.255.255.255 224-239 Multicasting Not used for subnetting
E 240.0.0.0 - 255.255.255.255 240-255 Experimental (reserved for future use) Not used for subnetting

Key Points

  • Class A: Supports up to ~16 million hosts per network.

  • Class B: Supports up to ~65,000 hosts per network.

  • Class C: Supports up to 254 hosts per network.

  • Class D: Used for multicasting, not for regular addressing.

  • Class E: Reserved for research and experimental purposes.

Most modern networks now use CIDR (Classless Inter-Domain Routing) instead of strict class-based addressing for flexibility and efficient address allocation.

If you notice Between Class A and Class B , there is on address left completely that is 127.0.0.0, this address is called as Loopback address aka localhost. So if you want to ping your system itslef, you use it

Thanks for reading it till here this is just to give you small ground as we move ahead in AWS we will be needing this details while creating VPC and Subnets

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Welcome to my dedicated AWS writing domain. Here, I break down cloud architecture, serverless systems, DevOps best practices, and practical AWS tutorials. This series centralizes all my cloud infrastructure deep dives into one unified space to help you build scalable and secure cloud applications.

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