Unbound DNS Resolver - Recursive DNSSEC Validated

AWS Networking
Base
Hardened build
minimal ports, security patches applied at build time
Access
Unique credentials
generated on first boot, readable only by root
Verified
Boots working
services pass a health gate before release
Support
24/7, 365 days
by email and live chat, 24 hour response SLA

Overview

Deploy a hardened, DNSSEC-validating recursive DNS resolver in minutes - not hours. Keep DNS traffic private and under your control instead of relying on third-party public resolvers.

Why the cloudimg image

This image arrives installed, configured and hardened, so there is no manual setup before you can use it. It is built on a patched base, runs with credentials generated uniquely for your instance on first boot, and passes an automated health check before every release. Every deployment is backed by 24/7 support from cloudimg engineers.

Key features

  • Resolve in minutes, not hours: Unbound arrives fully installed, hardened and answering queries on launch - skip the manual compilation, configuration and security lock-down of a DIY build. DNSSEC validation, QName minimisation, prefetch and aggressive NSEC caching are on by default. Keep your DNS traffic private and under your control instead of forwarding to third-party public resolvers where you lose visibility and DNSSEC guarantees.
  • Secure by default with zero baked-in credentials: recursion is restricted to loopback and RFC1918 private ranges out of the box, so the instance can never be abused as a DNS amplification reflector - unlike a misconfigured manual install. unbound-control runs on a root-only local UNIX socket with no TLS certificate or password shipped in the image. Integrates with Amazon VPC security groups and can forward zones to Amazon Route 53 Resolver endpoints.
  • 24/7 expert technical support from cloudimg with a one hour average response time for critical issues - a level of backing unavailable from unsupported community AMIs or DIY installs. Our engineers help with client access control, DNSSEC validation, Route 53 forwarding zones, cache and rate-limit tuning, CloudWatch integration and version upgrades.

Description

This is a repackaged open source software product wherein additional charges apply for cloudimg support services.

This is a repackaged open source software product wherein additional charges apply for cloudimg support services. ## Why This AMI Instead of DIY or a Public Resolver Unbound is a fast, security-focused, open source validating, recursive and caching DNS resolver from NLnet Labs. This AMI delivers Unbound fully installed, hardened and resolving within minutes of launch - replacing hours of manual compilation, configuration and lock-down. Instead of forwarding your DNS to a third-party public resolver like 8.8.8.8 (where you sacrifice query privacy and have no DNSSEC guarantee), this instance resolves names itself: it walks the DNS hierarchy from the root servers down, cryptographically validates every signed answer with DNSSEC, and caches results so repeat lookups are answered instantly from memory. Your DNS traffic stays under your control. ## Secure by Default - Never an Open Resolver The shipped configuration restricts recursion to loopback and the RFC1918 private address ranges only. A recursive query from an arbitrary internet source is answered with REFUSED, so this instance can never be abused as a DNS amplification reflector. Opening the resolver to more of your own client subnets is a single documented configuration change, and the user guide walks you through it. This is a self-hosted resolver for your own authorized clients - it is not a public DNS service, an anonymizer or an open resolver. ## DNSSEC Validation Out of the Box Unbound seeds the public root trust anchor with unbound-anchor and validates every recursive answer: a signed name is returned with the Authenticated Data (AD) flag set, while a name with a deliberately broken signature (dnssec-failed.org) is rejected with SERVFAIL rather than handed to your clients. The build proves both scenarios, plus that a repeat query is served from the in-memory cache. ## No Default or Shared Credentials A DNS resolver has no user login; its only management surface is unbound-control, which is configured here on a root-only local UNIX socket with no TLS certificate at all - so there is no control key or password baked into the AMI to leak or rotate. The management channel is never exposed to the network. Systemd-resolved's stub listener is disabled so Unbound owns port 53 cleanly. ## AWS Integration This AMI runs on Amazon EC2 and integrates naturally with your Amazon VPC networking. You can configure Unbound to forward specific private hosted zones to Amazon Route 53 Resolver inbound/outbound endpoints, keeping split-horizon DNS seamless. Security group rules on your EC2 instance control which VPC subnets and peered networks can reach port 53. For observability, export Unbound statistics via the CloudWatch Agent or push structured logs to Amazon CloudWatch Logs for centralized monitoring and alerting on query volume, cache hit ratios and SERVFAIL rates. The AMI can be launched via AWS CloudFormation or Terraform for repeatable, infrastructure-as-code deployments across multiple availability zones. ## Key Capabilities - High-performance recursive resolution with in-memory cache and prefetch

  • Full DNSSEC validation of signed zones
  • QName minimisation for query privacy
  • Aggressive NSEC caching
  • Response and per-IP rate limiting plus identity/version hiding and glue hardening to blunt cache poisoning and reflection
  • Small, auditable, single-service footprint with no database to run
  • DNS over TLS support ## Get Started SSH in as your instance's default login user, confirm the resolver with dig @127.0.0.1 example.com, add your own client subnets to access-control, then point your workloads and networks at this instance for DNS resolution. cloudimg engineers can walk you through client access control, DNSSEC validation, forwarding zones, Route 53 integration and performance tuning after purchase. Unbound is a trademark of NLnet Labs. This image is produced by cloudimg and is not affiliated with, sponsored by or endorsed by NLnet Labs. All other product and company names are trademarks or registered trademarks of their respective holders; use of them does not imply any affiliation or endorsement.

Related technologies

recursive dns resolverdnssec validationcaching dnsself hosted dnsdns securityprivate dns resolverdns amplification protectionvpc dnsdns cache serveropen source dns