This comprehensive guide contrasts the seminal IPv4 protocol that connects devices to the Internet with its next-generation replacement IPv6. If you have ever wondered about the tech powering internet connectivity to billions of devices worldwide, this is the article for you!
We first rewind a few decades to see what compelled the creation of IPv6 to replace proven IPv4 technology. We then dive deep on their technical differences in addressing schemes, packet transmission, routing infrastructure, security, and mobility capabilities. We also look at where both protocols stand today and roadmaps to IPv6 becoming the dominant internet protocol.
The Origins Story Behind IPv6
Launched for commercial internet access in 1983, the Internet Protocol Version 4 (IPv4) powered seamless global communication between public and private computer networks. Its addressing framework provided approximately 4.3 billion unique addresses to connect devices and route data packets between them.
During the internet connectivity boom of the 1990s, scientists foresaw IPv4 addresses getting exhausted within decades given the pace of growth:
Year IPv4 Addresses Used
1994 33,000
1995 4,213,000
1996 16,047,000This projected address depletion coupled with other structural limitations like small packet header size and lack of native security compelled the Internet Engineering Task Force (IETF) to develop the next generation Internet Protocol Version 6 (IPv6).
Let‘s breakdown the key enhancements and differences between the two protocols.
IP Address Length: 32-bits vs 128-bits
The most talked about differentiation between IPv4 vs IPv6 is the address space length. IPv4 uses 32 bits to represent IP addresses while IPv6 expands it to 128-bit addresses.
Address Space Comparison:
| Protocol | Address Length | Total Address Space | Address Space Ratio |
|---|---|---|---|
| IPv4 | 32 bits | 2^32 = 4 billion | 1 |
| IPv6 | 128 bits | 2^128= 3.4×10^38 | 8.5×10^28 times IPv4 |
To contrast representation, the same public IP would be written as:
IPv4: 172.105.36.5
IPv6: 2001:0db8:85a3:0000:0000:8a2e:0370:7334The below IPv6 address breaks down into 8 groups of 4 hexadecimal numbers mapped to 16 bits each.
This gigantic capacity ensures no risk of addresses getting exhausted even with Internet of Things (IoT) projections reaching 125 billion connected devices by 2030!
Header Changes, Routing & Mobility Support
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Table showing evolution metrics across technical capabilities between the protocols.
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The Transition Mechanism to IPv6
Migrating the world‘s networks from IPv4 to IPv6 doesn‘t happen overnight. It needs compatibility techniques that allow both protocols to co-exist in the interim across the fragmented transition timeline of different regions.
The dual-stack mode became the elegant solution that enabled IPv4 and IPv6 integration on the same networks. Here it provides a tunnel across specific security gateways that translate traffic between the protocols. This allows newer devices and traffic to use native IPv6 while legacy IPv4 systems remain active for migration.
The diagram below conceptually depicts this IPv4/IPv6 dual-stack coexistence:
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Analysts predict the Asia Pacific region fully migrating network infrastructure to IPv6 by 2025. As other world regions follow suit and IPv4 address allocations diminish, IPv6 is clearly the future.
Conclusion: The Winding Road to Upgraded Internet Protocols
Transitioning deeply entrenched foundational technology like IP is akin to changing engines mid-flight. It requires extensive coordination between standards bodies, vendors, service providers and end users across the technical ecosystem.
While IPv4 has capably supported the stunning growth of the Internet so far, its address depletion risks required a new unencumbered protocol. IPv6 stands as a future-ready Internet backbone engineered via decades of global collaboration. This ensures continuity of the incredible digital progress we have seen so far with much more innovation yet to come!
IPv4 IPv6
Users 4 billion 3.4×10^38
Trajectory Decline after 2025 Dominant protocol 