IP address management: what it means for DNS and routing teams

TL;DR: IP addresses still underpin routing, DNS resolution, and device identification, but the article shows that IPv4 exhaustion, dual-stack complexity, and IPv6 adoption gaps are now shaping operational risk for network and security teams, according to DigiCert. The bigger lesson is that addressing is no longer just a networking concern; it is a governance problem for connected identity at scale.

NHIMG editorial — based on content published by DigiCert: What is an IP Address

By the numbers:

• Data from Google shows IPv6 global adoption reached just under 50% as of early 2025.
• In 2011, IANA officially exhausted its pool of unallocated IPv4 addresses.

Questions worth separating out

Q: How should security teams use IP addresses in access decisions?

A: Security teams should use IP addresses as supporting telemetry, not as a primary trust signal.

Q: Why do IPv4 limitations still matter for identity and security programmes?

A: IPv4 limitations still matter because many access controls, logs, and service designs were built around a world where addresses felt stable and plentiful.

Q: What breaks when organisations rely on static IP assumptions?

A: Static IP assumptions break when services move, scale, or share infrastructure.

Practitioner guidance

• Inventory address-dependent controls Map every place where firewall rules, allowlists, certificate validation, monitoring, or service access still depends on a stable IP.
• Validate dual-stack DNS governance Check that A and AAAA records are managed together, tested together, and monitored together so one protocol does not drift out of sync with the other.
• Separate network location from trust decisions Use IP data for routing and telemetry, not as a primary trust signal for access decisions.

What's in the full article

DigiCert's full blog covers the operational detail this post intentionally leaves for the source:

• Step-by-step explanation of IPv4, IPv6, NAT, and CIDR for practitioners who need the protocol mechanics.
• Examples of A, AAAA, and dual-stack DNS record handling for mixed-client environments.
• Allocation hierarchy details from IANA to RIRs and local registries, useful for understanding address governance.
• Practical discussion of IPv6 rollout barriers across ISPs, hardware, and DNS management.

👉 Read DigiCert's guide to IP addresses, IPv4, IPv6, and DNS routing →

IP address management: what it means for DNS and routing teams?

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