A Farewell to ARPs: IPv4 Service on IPv6-Only Networks
11 hours ago
- #IETF draft
- #ARP elimination
- #IPv6-only
- IPv6-only networks still rely on IPv4 subnets and ARP, which introduces operational costs and complexity.
- The IETF proposal introduces a sentinel IPv4 address (192.0.0.11) that allows IPv4 to operate over IPv6-only infrastructure without ARP or IPv4 subnets.
- ARP causes issues like storms, poisoning, and table exhaustion, while IPv4 addresses waste space and require subnet management.
- Some hosting providers already use non-standard solutions (e.g., Hetzner, OVHcloud, Scaleway), but lack interoperability.
- The proposal uses DHCPv4's Router Option unchanged, so existing systems work, and hosts resolve the gateway's MAC via IPv6 neighbor cache.
- This eliminates dual-stack overhead, reduces IPv4 address waste, improves security, and allows gradual adoption with no flag day.
- A universal gateway address (192.0.0.11) could standardize configurations across providers, enhancing interoperability.
- Reference implementations exist for Linux, and fallback mechanisms support unmodified hosts (e.g., Windows, macOS).
- The draft is under IETF IntArea review, with operator community feedback encouraged to drive adoption.