DNS Outage & Solution
Building Unkillable Domain Name Infrastructure
Executive Summary
The AWS October 2025 outage highlighted the catastrophic impact of DNS server failures on modern infrastructure. When the internet's "phonebook" goes down, organizations lose the ability to connect users to services, even when the underlying infrastructure remains operational.
While direct IP address access seems like an obvious workaround, modern cloud architecture in 2025 makes this approach technically infeasible due to Server Name Indication (SNI), SSL/TLS certificate validation, and dynamic IP allocation. This document outlines three proven strategies to build resilient DNS infrastructure that can survive coordinated nation-state attacks on major cloud providers.
The recommended approach implements a "Hidden Master" architecture using geographically and geopolitically diverse providers, creating a DNS system that requires simultaneous compromise of Swedish infrastructure foundations, US enterprise specialists, and physical hardware in independent data centers—a coordination level beyond the capability of most threat actors.
The Problem: Why Direct IP Addresses Fail in Modern Architecture
During the AWS outage, DNS failed for many websites. The intuitive solution—substituting website
names with their respective IP addresses—proved completely ineffective. If you tried to type
54.23.12.99 into your browser during the outage, it almost certainly would have failed.
🔐 SNI (Server Name Indication)
The Biggest Blocker:
Modern servers host thousands of websites on a single IP address. When your browser connects,
it must send the website name (e.g., bank.com) in the handshake so the server
knows which website to show you. If you just send an IP, the server doesn't know who you're
looking for and will drop the connection or return an error.
🔒 SSL/TLS Certificates
Security Mismatch:
Security certificates are tied to domain names (bank.com), not IP addresses.
If you type an IP address, the browser will display "Not Secure" warnings because the
certificate doesn't match. Most financial applications will block the connection entirely
at this point.
🔄 Dynamic IPs
Ephemeral Infrastructure:
In AWS and modern cloud platforms, IP addresses are ephemeral—they change when servers restart or scale up. Hardcoding an IP is like writing down a taxi's license plate number and expecting the same taxi to pick you up every day. It simply doesn't work in dynamic cloud environments.
The Solution: Making DNS Unkillable
Since we can't use IP addresses, we must make the "phonebook" (DNS) itself unkillable. Here are three layers of defense to implement immediately:
Layer 1: Tune Your TTL (Time To Live)
TTL tells other computers how long to "remember" your IP address before asking for it again.
❌ The Mistake
Many companies set low TTLs (e.g., 60 seconds) to make changes quickly. This means if DNS goes down, customers lose access after 60 seconds.
✅ The Fix
Increase TTL for core endpoints (like your main login page) to 1 hour or more during stable periods.
🎯 The Result
If DNS crashes, anyone who visited your site in the last hour still has the address "memorized" in their browser or ISP cache. They can still connect even if the DNS server is burning.
Layer 2: The "Lifeboat" Domain (Out-of-Band Status)
During the AWS crash, many banks couldn't even tell customers "We are down" because their status pages were also on AWS.
The Solution: Create a Completely Separate Status Page Infrastructure
- Host it elsewhere: Put a static HTML page on a different provider (not AWS/Google/Azure).
- Different TLD: If your main site is
bank.com, buybank-status.com. - Hardcoded DNS: Manage this domain's DNS through a registrar that is not on your primary target providers.
🎯 The Result
When the main ship sinks, you have a lifeboat. You can direct frustrated users to
bank-status.com to communicate with them, reducing panic and call center volumes.
Layer 3: Geopolitical & Structural Diversity
The AWS DNS outage revealed a critical vulnerability: supply chain concentration risk. In a geopolitical cyberwar scenario (like a coordinated attack on AWS/Google/Cloudflare), targeting the "Big 3" is the most efficient way for an adversary to cripple the Western financial sector.
If your threat model includes nation-state actors targeting US-centric hyperscalers, moving to "Boutique" or "Sovereign" infrastructure is the correct strategic move.
Provider Strategy: Beyond the Big 3
Here is a strategy to build DNS architecture using providers that are technically robust but geopolitically or structurally distinct from major US cloud aggregators.
🇪🇺 Option 1: The "Sovereign" Approach
High-Integrity European Infrastructure
If the attack is targeted at US tech giants, utilizing infrastructure based in neutral or highly regulated jurisdictions offers a "geopolitical hedge."
Netnod (Sweden)
Why them: Netnod is not a standard commercial cloud; they are an internet infrastructure foundation. They actually operate one of the world's 13 logical Root Name Servers (i-root).
The Advantage: They are built for extreme resilience and are structurally vital to the internet itself, making them harder to take down than a commercial cloud. They run their own bare-metal hardware and fiber, independent of AWS/Google.
SWITCH (Switzerland)
Why them: They manage the .ch top-level domain and the academic
backbone of Switzerland.
The Advantage: Swiss jurisdiction, neutral ground, and infrastructure designed for national resilience rather than commercial scaling.
🎯 Option 2: The "Specialist" Approach
Pure-Play DNS Providers
These companies do one thing: DNS. They do not run generic compute clouds (EC2/Lambda), which reduces their "attack surface" for exploits targeting hypervisors or orchestration layers.
DNS Made Easy / Constellix (owned by DigiCert)
Why them: They are enterprise-grade but operate on their own distinct IP ranges and hardware. They are famous for having exceptionally high uptime histories because they don't have the complexity of a general cloud provider.
Rage4 (Europe/Poland)
Why them: A smaller, performance-obsessed provider. They use a completely different software stack. If a hacker finds a zero-day exploit in the standard software AWS uses, Rage4's custom stack likely won't be affected.
☢️ Option 3: The "Nuclear" Option
Self-Hosted Anycast (BYOIP)
If you truly cannot trust any third-party provider to stay up, you must become your own provider. This is how the largest banks used to do it, and many are returning to this model for their "Lifeboat" systems.
How It Works:
- Get Your Own IP Block: Register your own ASN (Autonomous System Number) and IP range.
- Colocation (Colo): Place physical "pizza box" servers in carrier-neutral data centers (like Equinix or Telehouse)—not AWS data centers.
- Anycast: Announce your IP address from 3 or 4 different physical locations (e.g., London, Frankfurt, Singapore, New York).
🎯 The Result
You are now totally independent of the cloud. Unless the attacker takes down the actual undersea cables or the global BGP routing table, your DNS stays up.
Recommended Architecture: The "Hidden Master"
To manage this mix of "Small/Sovereign" providers without creating an administrative nightmare, use a Hidden Master architecture.
| Component | Description | Purpose |
|---|---|---|
| The Brain (Hidden Master) |
A small, private DNS server inside your secure corporate network. No one on the internet knows this server exists. | Central control point for all DNS records. Not publicly accessible. |
| Provider A (Netnod) |
Swedish Internet Foundation infrastructure | Geopolitical diversity, internet infrastructure foundation |
| Provider B (DNS Made Easy) |
US-based enterprise specialist | High uptime, pure-play DNS, different architecture |
| Provider C (Self-Hosted) |
Small bare-metal server in London data center | Complete independence from cloud providers |
The Flow:
- When you update a record on your "Hidden Master," it automatically pushes the data to Providers A, B, and C simultaneously.
- Public queries are served by A, B, or C—never by the Hidden Master directly.
- If any provider fails, the others continue serving requests.
🎯 The Strategic Outcome
For an attacker to take you offline, they would have to coordinate a simultaneous strike against:
- The Swedish Internet Foundation (Netnod)
- A US-based enterprise specialist (DNS Made Easy)
- Your specific physical hardware in a London basement
This level of coordination is significantly harder than simply targeting us-east-1.
This is the resilience we are looking for.
Implementation Checklist
Increase TTL values: Set core endpoint TTL to 1+ hours during stable periods
Create lifeboat domain: Register yourcompany-status.com on different provider
Assess provider concentration: Identify DNS dependencies on Big 3 (AWS/Google/Cloudflare)
Select diverse providers: Choose 2-3 providers from different categories (Sovereign/Specialist/Self-Hosted)
Implement Hidden Master: Set up private DNS server with automated replication
Consider self-hosting: Evaluate BYOIP/Anycast for critical infrastructure
Key Lessons from AWS DNS Outage
🎯 Single Point of Failure
Relying on a single DNS provider—even AWS Route 53—creates catastrophic risk. Geographic redundancy within one provider is insufficient.
🌍 Geopolitical Concentration
US-based cloud providers are strategic targets. Nation-state actors can achieve maximum impact by attacking the Big 3 simultaneously.
⏱️ Cache is Critical
High TTL values provide a buffer during outages. Organizations with 60-second TTLs went offline immediately; those with 1-hour TTLs maintained service.
📡 Communication Channels
Without an independent status page, organizations had no way to communicate with customers during the outage, amplifying panic and support costs.