| Feature | IPv4 | IPv6 |
|---|---|---|
| Address Length | 32-bit (4 octets) | 128-bit (8 groups of 4 hexadecimal digits) |
| Address Format | Decimal, represented as four decimal numbers separated by dots (e.g., 192.168.0.1) | Hexadecimal, represented as eight groups separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334) |
| Total Address Space | ~4.3 billion addresses (2^32) | 340 undecillion addresses (2^128) |
| Address Examples | 192.168.1.1, 10.0.0.1 | 2001:0db8:85a3:0000:0000:8a2e:0370:7334 |
| Subnetting | Uses subnet masks (e.g., 255.255.255.0) | Uses prefix length (e.g., /64) |
| Address Configuration | Manual (static) or DHCP | Stateless Address Autoconfiguration (SLAAC) or DHCPv6 |
| Broadcast | Supports broadcast communication | No broadcast, uses multicast and anycast |
| Security | Security is optional and implemented via IPsec | IPsec is mandatory and built into the protocol |
| Header Complexity | More complex, with 20-byte header including optional fields | Simpler, fixed 40-byte header, improving efficiency |
| Fragmentation | Performed by routers and sending host | Performed only by the sending host |
| Checksum | Includes a header checksum | No checksum (improves processing speed) |
| NAT (Network Address Translation) | Commonly used due to limited address space | Not necessary due to vast address space |
| IPv4 Mapped IPv6 Addresses | Not applicable | ::ffff:<IPv4 address> (e.g., ::ffff:192.168.1.1) |
| Compatibility | Widely used and supported | Growing adoption, with dual-stack (IPv4/IPv6) support |
| Transition Mechanisms | N/A | Tunneling, Dual-Stack, and Translation (e.g., NAT64) |
Key Differences:
- Address Length: IPv6 has a significantly larger address space with 128-bit addresses compared to IPv4’s 32-bit.
- Security: IPv6 mandates IPsec support, enhancing security features compared to IPv4, where security is optional.
- Address Configuration: IPv6 supports stateless address autoconfiguration, making it easier to manage in large networks.
- Header Structure: IPv6 has a simpler and more efficient header structure compared to IPv4.
Conclusion:
IPv6 was designed to overcome the limitations of IPv4, primarily the limited address space, and to improve overall network efficiency, security, and configuration. As the world transitions to IPv6, understanding both protocols is essential for modern network management and design.