Notifications
Clear all
Topic starter
23/06/2026 7:06 pm
TL;DR: DNS failover lets traffic reroute to a secondary endpoint when the primary IP or hostname is unavailable, reducing downtime from outages, DDoS, and DNS disruption, according to DigiCert. For identity and access teams, the larger lesson is that availability controls must sit alongside access controls, because service continuity increasingly depends on the identities and endpoints that DNS directs.
NHIMG editorial — based on content published by DigiCert: DNS Failover
Questions worth separating out
Q: How should security teams implement DNS failover for critical services?
A: Start with the services whose unavailability would stop authentication, customer access, or workload communication.
Q: Why does DNS failover matter to IAM and access governance?
A: Because DNS is often the first dependency that user access and service access encounter.
Q: What breaks when DNS failover is configured but the backup path is not independent?
A: The organisation gets the appearance of resilience without actual continuity.
Practitioner guidance
- Inventory identity-dependent services first Map which customer, workforce, and workload applications rely on DNS to reach authentication, API, or portal endpoints, then rank them by business criticality.
- Validate true failure-domain separation Confirm that the secondary IP, hostname, region, or provider can still serve the workload when the primary path is down, rather than sharing the same dependency chain.
- Test failover under realistic outage conditions Run controlled exercises that simulate endpoint failure, DDoS-style saturation, and DNS unreachability so the team can confirm detection, rerouting, and restoration behaviour.
What's in the full article
DigiCert's full blog post covers the operational detail this post intentionally leaves for the source:
- Step-by-step explanation of how primary and secondary DNS responses are evaluated before traffic is rerouted.
- The article's examples of outage handling across cloud services and customer-facing applications.
- The specific monitoring cadence and failover behaviour described by the vendor for service continuity planning.
- The vendor's positioning on when DNS failover should be treated as a standard practice for availability.
👉 Read DigiCert's explanation of DNS failover for service availability →
DNS failover and uptime: is your resilience model keeping up?
Explore further
25/06/2026 2:55 am
DNS availability is now an identity dependency, not just an infrastructure concern. When DNS fails, users, workloads, and even access workflows lose the path they need to reach identity-controlled services. That makes routing resilience part of identity governance, because an unavailable service is functionally indistinguishable from a denied one to the end user. Practitioners should treat DNS as part of the access chain, not a separate reliability problem.
A few things that frame the scale:
- 67% of organisations still rely heavily on static credentials despite the risks they pose to agentic AI deployments, according to The 2026 Infrastructure Identity Survey.
- Only 44% of organisations have implemented any policies to manage their AI agents, despite 92% agreeing that governing AI agents is critical to enterprise security.
A question worth separating out:
Q: Who should own DNS failover decisions when an outage starts?
A: Ownership should sit with the teams responsible for service availability, identity-dependent access, and incident response, not with one silo alone. The decision to fail over affects user experience, authentication paths, and customer communications, so organisations need a documented authority chain before the outage occurs.
👉 Read our full editorial: DNS failover is becoming a baseline availability control
