IPv6 vs IPv4: Why Free 128-bit Addresses Beat the $26.81 IPv4 Tax

IPv6 already carries 35% of global internet traffic, and it costs nothing to provision. IPv4 leases keep getting more expensive. Here's the math and the migration mechanics.

The price curve is the argument

Legacy IPv4 addresses averaged $26.81 between January 2025 and February 2026 — up from a historical low of $5 in 2011. IPv6 blocks, by contrast, are routinely provisioned for free: a /48 block costs nothing because the 128-bit space holds roughly 340 undecillion addresses.

Metric	IPv4 Legacy	IPv6 Native
Avg. latency	Baseline	Lower
Packet loss	Higher variance	0.5%
Global share	Declining majority	35% (early 2026)

Why v6 packets are cheaper to forward

The fixed 40-octet IPv6 header removes per-hop work: no header checksum, no router-side fragmentation, options moved to extension headers. Routers skip integrity checks on every hop, and fragmentation happens at the source only.

Feature	IPv4 Header	IPv6 Fixed Header
Base size	Variable (20–60 bytes)	Fixed 40 octets
Checksum	Required	Absent
Fragmentation	Router and host	Host only
Options	In header	Extension headers

Three migration paths, one realistic answer

• Dual-stack — run both stacks; Happy Eyeballs prefers v6 when both record types exist. This is the sane default.
• Tunneling — wraps v6 in v4, but shrinks MTU and adds latency. A stopgap, not a strategy.
• NAT64 — the translation mechanism for networks where the ISP supplies only one public-facing v6 address.

The shortcut rule for shortening v6 addresses

Remove leading zeros per hextet, then replace the longest run of zero hextets with :: — exactly once. Expand back to eight groups to verify. Non-canonical forms get rejected by validation tools.

Rule	Action	Example
Leading zeros	Remove preceding zeros	0042 → 42
Zero compression	Replace longest run with ::	2001:0:0:1::

What I'd actually do

Audit your cloud vendor for the free IPv6 blocks already sitting in your account, publish AAAA records, delegate ip6.arpa for reverse lookups, and let Happy Eyeballs do the steering. Migration costs engineering time; staying put costs a lease bill that compounds — CGNAT overhead, dual-stack maintenance, $26.81 per address.

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первоисточник: wirez.top