New patches allow building Linux IPv6-only

Original Article ↗ Hacker News Discussion ↗

Scope of the Patch / April Fools Context

  • Patchset allows Linux to be built IPv6-only, or with either protocol alone; some see this as a useful cleanup of config options.
  • It originated as an April Fools joke, but parts (like cleaner separation of IPv4/IPv6 options) are proposed seriously.
  • Concerns arise that language like “legacy IP” signals hostility to IPv4, though the patch doesn’t remove IPv4 support.

IPv6 Adoption, Policy, and Incentives

  • Some argue IPv6 won’t reach full adoption without government intervention; current global usage appears to be plateauing.
  • Others note big tech and CDNs already benefit from IPv6 (less congestion, redundant paths), while many “eyeball” ISPs lag.
  • ISPs are criticized for dragging their feet despite owning IPv6 space; CGNAT cost and complexity are seen as a driver toward IPv6.

NAT vs Public Addressing, Security, and Privacy

  • Strong disagreement over NAT: some call it a “horrible hack” that breaks end-to-end networking and fuels centralization; others like it as a simple safety net and barrier to per-device billing.
  • Multiple posters stress NAT is not a true security mechanism, though it can reduce exposed surface; real protection should come from firewalls.
  • Privacy debates center on:
    • Fear of ISPs easily counting devices or tracking them via stable IPv6 addresses.
    • Counterpoints that privacy extensions, temporary addresses, and huge address space make device counting unreliable.
    • Acknowledgment of IPv6 “footguns” (e.g., MAC leakage) if privacy features aren’t enabled.

Practical Barriers: Services, Tooling, and IPv6-Only Environments

  • Running IPv6-only systems is described as painful:
    • Many services lack AAAA records or IPv6 origins (e.g., GitHub, some AWS services, certain CDNs and load balancers).
    • Common tooling (Docker, some gateway proxies, subscription tools) often assumes IPv4 and breaks on IPv6-only hosts.
  • Some want true IPv6-only CI environments where IPv4 socket creation fails, to expose and fix such assumptions.

Usability, Home Networking, and DNS

  • Users worry about:
    • Multiple addresses per interface.
    • Publicly addressable IoT/consumer devices if firewalls are misconfigured.
    • Rotating prefixes vs static ones for privacy and home servers.
  • Others argue:
    • Proper default firewalls plus local VLANs/segmentation solve exposure concerns.
    • DNS/mDNS/zeroconf should make addresses rarely typed by hand; resistance to IPv6 literals is seen as a solved problem in principle, though mDNS reliability is disputed.

Philosophy, Freedom, and Backward Compatibility

  • Some see calls to penalize or deprecate IPv4 as coercive, especially for legacy equipment and stable IPv4-based networks.
  • Others explicitly want IPv4 to become painful (“legacy IP”) so that v4-only users experience the same friction as v6-only users, hoping to force progress.
  • There is broad agreement that IPv4 and IPv6 coexist today; disagreement is over whether coexistence should remain indefinite or be intentionally phased out.