IPv4 addresses are scarce; IPv6 is the long-term fix. Running dual-stack (IPv4 + IPv6) keeps compatibility while enabling IPv6. Plan for IPv6 in new deployments and test DNS and firewalls for both families.
Dual-stack (IPv4 + IPv6)
- Your server and network listen on both IPv4 and IPv6.
- DNS can return A and AAAA records so clients use either.
- Compatibility with legacy clients (IPv4-only) and modern ones (IPv6).
- Most hosting providers support dual-stack; enable it when available.
IPv4 scarcity and cost
- New IPv4 addresses are limited; some providers charge extra or restrict how many you get.
- IPv6 addresses are abundant; no per-address scarcity.
- Plan to rely less on IPv4 over time (e.g. shared vs dedicated IP, NAT where appropriate).
What to do
- New deployments: Enable IPv6 and dual-stack; test DNS (A and AAAA) and firewall rules for both.
- Existing: Add IPv6 where possible; ensure monitoring and security tools understand both.
- IPv6-only: Possible in some environments but not yet universal; dual-stack is the safe default.
Summary
Dual-stack keeps compatibility and enables IPv6. IPv4 may cost more or be limited; plan for IPv6 and test DNS and firewall for both families.
