IPv4 vs IPv6
Two address families running the internet. Understand capacity, notation, and the inevitable migration.
The internet is built on IP addresses, unique identifiers that allow computers to find each other. For decades, we've relied on IPv4 (Internet Protocol version 4). However, as more devices come online, we've run out of addresses, leading to the adoption of IPv6.
To extend the life of IPv4, technologies like CIDR (Classless Inter-Domain Routing) were invented, but the ultimate solution is the transition to 128-bit addresses.
Quick Summary
IPv4
Uses 32-bit addresses (e.g., 192.0.2.10). Limited to ~4.3 billion addresses.
IPv6
Uses 128-bit addresses (e.g., 2001:db8::10). Virtually infinite address space.
Key Differences
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address Length | 32-bit | 128-bit |
| Notation | Decimal (192.168.1.1) | Hexadecimal (2001:db8::1) |
| Total Addresses | ~4.3 Billion | 340 Undecillion |
| Configuration | DHCP or Manual | SLAAC (Auto-config) |
DNS Records
A domain can publish both record types to support both protocols. This is known as "Dual Stack".
Frequently Asked Questions
Do I need both IPv4 and IPv6?
Yes, for maximum compatibility. While IPv6 is the future, many legacy systems and networks still rely exclusively on IPv4. Running both (Dual Stack) ensures everyone can reach your content.
Is IPv6 faster than IPv4?
Theoretically, yes. IPv6 header structures are simpler, reducing router processing time. It also eliminates the need for NAT (Network Address Translation), which can reduce latency in some scenarios.