IPv6 Addressing Overview
- Networking Fundamentals & OSI Model
- TCP/IP Model
- Network Topologies
- IP Addressing & Subnetting
- Routing Algorithms & Protocols
- Switching Concepts
- Transport Layer Protocols (TCP & UDP)
- Application Layer Protocols
- Network Security & Firewalls
- Wireless Networking & Wi-Fi
- Network Address Translation (NAT)
- DNS Deep Dive
- Congestion Control & Flow Control
- Error Detection & Correction
- Network Devices
- VPN & Tunneling
- Load Balancing & CDN Networking
- Socket Programming
- Network Troubleshooting Tools
- Physical Layer & Transmission Media
- Data Link Layer & MAC Addressing
- Ethernet Protocol
- ARP (Address Resolution Protocol)
- ICMP Protocol
- Unicast, Multicast, Broadcast and Anycast
- Proxy Servers
- Port Numbers Reference
- Network Performance Metrics
- Quality of Service (QoS)
- Software-Defined Networking (SDN)
- HTTP/2 and HTTP/3 Overview
- 5G and Mobile Networks
- IoT Networking Basics
- VoIP Networking Basics
Why IPv6 Was Created
IPv4's 32-bit addresses allow for roughly 4.3 billion unique values - a number the internet has already effectively exhausted. IPv6 solves this with 128-bit addresses, providing an astronomically larger address space that won't run out in any realistic future.
What an IPv6 Address Looks Like
2001:0db8:0000:0000:0000:ff00:0042:8329It's written as eight groups of four hexadecimal digits, separated by colons - a very different look from IPv4's dotted decimal format.
Two Rules for Writing It More Compactly
- Leading zeros can be dropped within each group:
0db8becomesdb8. - One run of consecutive all-zero groups can be replaced with
::, but only once per address.
Full: 2001:0db8:0000:0000:0000:ff00:0042:8329
Shortened: 2001:db8::ff00:42:8329IPv4 vs IPv6 at a Glance
| IPv4 | IPv6 | |
|---|---|---|
| Address length | 32 bits | 128 bits |
| Total addresses | ~4.3 billion | Effectively limitless for practical purposes |
| Format | Dotted decimal (192.168.1.1) | Hexadecimal groups (2001:db8::1) |
| NAT needed? | Commonly, due to scarcity | Rarely - enough addresses for every device directly |
Why Both Still Coexist Today
IPv6 adoption has grown steadily, but IPv4 remains deeply embedded in existing infrastructure. Most networks today run in a "dual-stack" mode, supporting both IPv4 and IPv6 simultaneously, during this long, gradual transition period.