Understanding Nameserver Delegation in DNS: A Case Study with Cloudflare and Google Cloud DNS

Managing domain names can get complicated fast, especially when youʼre working with multiple environments like production and staging. One powerful technique that can help is nameserver delegation. In this post, weʼll explore the concept of nameserver delegation and give a practical example of how I separated the routing of a staging subdomain (staging.example.com) from the main domain (example.com) using Cloudflare and Google Cloud DNS.

What is Nameserver Delegation?

Nameserver delegation allows you to distribute DNS management for various sections of your domain among different providers. In simple terms, it involves assigning the responsibility for a subdomainʼs DNS records to a different set of nameservers.

For example, letʼs say you own example.com but want staging.example.com to be managed by a separate DNS provider. Nameserver delegation makes this possible, keeping each part of the domain independently managed, which is incredibly useful in certain setups.

Why Use Nameserver Delegation?

Hereʼs why you might want to go this route:

Unique Security Needs: Separate SSL certificates for the main domain and subdomains can boost security.

Independent Environments: Different environments (like production and staging) can have unique DNS settings.

Better Load Distribution: Splitting up DNS responsibility across providers can ease the load on any one provider.

Custom Configurations: You get more flexibility to apply specific DNS features or policies to subdomains.

Case Study: Delegating Nameservers for example.com
The Clientʼs Requirements and Why Delegation Was Needed

My client came to me with a specific challenge: they needed to deploy the new domain example.com, with the main domain hosted on Cloudflare. However, their staging environment, which would use the subdomain staging.example.com, had distinct requirements that couldnʼt be met by their current DNS setup. They needed:

A Separate SSL Certificate for Staging: The client wanted to ensure that their staging environment could have its own SSL certificate, separate from production, to maintain secure testing without risking production configurations.

Independent DNS Management: The staging environment required DNS configurations that were distinct from the production environment, particularly because different services would be used for staging and production. This also meant the staging environment needed flexibility in terms of DNS routing and performance tuning.

Security and Isolation: To minimize any potential risks, they wanted to ensure the staging environment was isolated from the production environment in terms of DNS management, so any issues in staging wouldnʼt affect production operations.

Given these requirements, nameserver delegation was the most straightforward solution, as it allowed them to achieve both isolation and customization without impacting the main domain.

How I Set It Up
1. Main Domain on Cloudflare:

Firstly I set up the primary domain, example.com, on Cloudflare to take advantage of its DNS management features and SSL capabilities.

Cloudflareʼs nameservers would handle all DNS requests for example.com.

2. Staging Subdomain on Google Cloud DNS:

To keep the staging environment separate, I created a DNS zone for staging.example.com on Google Cloud DNS.

This allowed us to issue a separate SSL certificate for staging, ensuring that production and staging were independently secured and didnʼt interfere with each other.

3. Delegating Nameservers from Cloudflare to Google Cloud DNS:

In Cloudflare, I set up NS (Nameserver) dns type records for staging.example.com, pointing them to Google Cloud DNS where I had created the domain in the second step. This configuration allowed Cloudflare to manage DNS for example.com, while DNS queries for staging.example.com were routed to Google Cloud DNS.

How It Works in Practice

When someone makes a DNS query for example.com, Cloudflare responds as usual. But when a query is made for staging.example.com, Cloudflare recognizes that the query needs to be handled by Google Cloud DNS, so it forwards the request accordingly.

This delegation ensures that the staging environment has its own independent DNS management, including a separate SSL certificate and customized DNS configurations, while leaving the production domain untouched.

Benefits of this Approach

Enhanced Security: By having separate SSL certificates and DNS configurations for each environment, the client ensures that both their production and staging sites remain secure and isolated from each other.

Flexibility: Each environment can be configured independently, with the flexibility to apply specific DNS settings, routing policies, and performance configurations to staging and production.

Reliability: Using different DNS providers means that if one provider experiences downtime, it doesnʼt impact the other environment, making the whole setup more resilient.

Tradeoffs to Consider

While nameserver delegation has some clear benefits, it also introduces a few tradeoffs:

Higher Complexity: Managing DNS across multiple providers means more administrative work and configuration steps.

Troubleshooting Hiccups: When DNS issues arise, it can be challenging to determine if the problem lies with the primary domain provider or the subdomainʼs provider. It often requires some extra investigation.

Variations in Consistency: Different DNS providers may manage requests in varying ways, which can sometimes result in slight differences in the speed or reliability of DNS query handling.

Additional Costs: Depending on the providers you choose, using multiple services for DNS can lead to additional costs, particularly if youʼre subscribing to premium features on one or both.

Conclusion

Nameserver delegation is a valuable resource for managing intricate hosting configurations. By allocating subdomains to various DNS providers, you can enhance flexibility, security, and reliability. Nonetheless, it’s crucial to weigh the potential tradeoffs.. While itʼs perfect for businesses with complex DNS needs — like separating environments or needing custom configurations — delegation can add complexity and administrative overhead.

In this example, I successfully used nameserver delegation to isolate the staging environment from the main domain, providing a secure and flexible solution for my client. If youʼre managing multiple environments or need more customized DNS setups, nameserver delegation is definitely worth considering — but make sure it aligns with your overall goals.