route53

SKILL.md

Amazon Route 53

Overview

Domain expertise for configuring Amazon Route 53 DNS across the public and private resolution
paths: hosted zone records, traffic-steering routing policies, health checks, DNS Firewall,
Route 53 Profiles, VPC Resolver (also known as Route 53 Resolver) for hybrid and Outposts networks,
and Global Resolver.

This skill is a router. Each customer task maps to a procedure file under references/. Read the
matching reference in full before acting, then follow its constraints and steps. The reference
files are self-contained: each carries its own decision tables, constraints, procedure, and
troubleshooting.

Execute commands using the AWS MCP server when connected (sandboxed execution, audit logging,
observability). Fall back to the AWS CLI otherwise. All Route 53 Domains API calls are made in
us-east-1 regardless of where the customer works.

Which Route 53 task do you need?

Goal
Reference

Point a hostname or zone apex at an IP, AWS resource, or hostname
creating a public DNS record

Split traffic across endpoints in a ratio (blue/green, canary, A/B)
splitting traffic with weighted routing

Fail over between two Regions for disaster recovery
configuring failover routing

Monitor whether an endpoint is up and get alerted
setting up a health check

Block malicious domains for a VPC at the resolver
blocking malicious domains

Work out which DNS Firewall rule wins for a domain across multiple rule groups
identifying the effective DNS Firewall rule

Apply one DNS config across many VPCs and accounts
configuring Route 53 Profiles

Fan DNS Firewall out across many accounts org-wide
centralizing DNS Firewall with Profiles

Resolve private DNS both ways across a hybrid network
resolving private DNS for hybrid networks

Run VPC Resolver locally on an AWS Outposts rack
running VPC Resolver on Outposts

Give on-premises and remote clients one anycast DNS endpoint
setting up Global Resolver

Routing notes

Records vs routing policies. A plain hostname-to-target mapping is the public DNS record
task. Splitting or steering traffic (weighted, failover) is a separate routing-policy task with
its own reference. Start from the customer's intent, not the record type.

Health checks vs failover. A health check monitors an endpoint and raises alarms. The
failover routing policy decides where traffic goes when a check fails. They are two references
and are often used together: set up the health check, then wire it into failover.

DNS Firewall for one VPC vs many accounts. Authoring rules for a VPC is the blocking
reference. Fanning the same protection across accounts with Profiles and Firewall Manager is the
centralizing reference.

DNS Firewall authoring vs diagnosis. Creating or changing rules is the blocking reference.
Working out which rule already wins for a domain when several rule groups are associated (a read
and diagnostic task) is the identifying-the-effective-rule reference.

Profiles, two entry points. General Profile setup (attach resources, share via RAM, cost
and visibility tradeoffs) is the configuring-Profiles reference. Using Profiles specifically to
scale DNS Firewall org-wide is the centralizing reference.

VPC Resolver, three contexts. In-Region hybrid resolution, the Outposts-local resolver, and
the Global Resolver anycast endpoint are three separate references. Match the reference to where
the resolver runs.

Cross-service work

Pointing a custom domain at a CloudFront distribution, or failing over between CloudFront
distributions, is cross-service work owned by the separate route53-cloudfront skill. Use this
skill for the Route 53 side of pure-Route 53 tasks only.

Security Considerations

These apply across the Route 53 tasks below; each reference repeats the ones load-bearing for its
workflow.

You SHOULD use least-privilege IAM credentials provisioned through IAM roles (instance profiles,
SSO/IAM Identity Center session credentials, or aws sts assume-role) rather than long-lived IAM
user access keys, and prefer read-only credentials for inspection steps.

You SHOULD recommend encrypted DNS transport (DoT or DoH) over plaintext Do53 for resolver client
populations, since Do53 exposes queried domain names to on-path observers.

You MUST scope resolver-endpoint security group rules on port 53 to the on-premises CIDR ranges or
known DNS server IPs, never 0.0.0.0/0.

You MUST encrypt query log and notification destinations at rest: KMS on CloudWatch Logs log
groups, SSE-S3/SSE-KMS on S3 buckets, server-side encryption (SSE) on a Data Firehose stream, and
SSE on SNS topics, because DNS query logs and health-check notifications can reveal infrastructure
topology.

For Global Resolver, you MUST treat access-token value returned at create time as a secret;
store it in AWS Secrets Manager rather than in plaintext, and validate which client populations
each DNS view authorizes.

Additional Resources

Amazon Route 53 Developer Guide

Amazon Route 53 product page

Route 53 pricing