What is Internal DNS and External DNS?

Introduction

The Domain Name System (DNS) is the back-end system for internet functionality. This translates the human-friendly domain names to machine-readable IP addresses. While DNS seems straightforward, it is divided into two distinct types: Internal DNS and External DNS. DNS may seem simple,

but it plays two critical roles: managing private network resources (Internal DNS) and public internet services (External DNS). In this blog, we’ll explore both, highlighting their differences, benefits, and practical applications.

Table of Contents

1. What is Internal DNS?
2. What is External DNS?
3. Key Differences Between Internal and External DNS
4. Advantages Internal and External DNS
5. Common Challenges and Solutions
6. Practical Use Cases
7. Conclusion

What is Internal DNS?

Internal DNS operates within private networks, enabling secure and efficient access to internal resources like servers and printers. For instance, an employee accessing ‘finance.company.local’ can retrieve tools safely and quickly. Internal DNS can reduce external DNS query traffic by up to 70%, significantly improving the performance and speed of internal applications. For example, employees might use internal DNS to log in to ‘finance.company.local’ to securely access internal tools and resources.

• Organizations using Internal DNS can reduce external DNS query traffic by up to 70% significantly enhancing response times for internal applications
• Internal DNS can cache frequently accessed records, further enhancing speed and efficiency in network operations.

What is External DNS?

External DNS operates on the public internet, resolving domain names for websites and services accessible globally. When a user enters ‘example.com’ in their browser, External DNS resolves the domain and directs the user to the correct server, ensuring the website is accessible. External DNS also ensures redundancy and high availability, making it indispensable for handling millions of queries daily.

For instance, when a user types “example.com” into their browser, External DNS connects the user to the right server, making the website accessible.

• Approximately 90% of internet users rely on External DNS services from major providers such as Google Cloud DNS and AWS Route 53.
• External DNS servers handle millions of queries per second, ensuring high availability and performance during peak traffic.

Key Differences Between Internal and External DNS

Understanding the distinction between Internal and External DNS is vital for effective network management. Here’s a detailed comparison of the characteristics that make them stand out:

Purpose

• Internal DNS: Manages private resources within an organization, such as internal servers and applications.
• External DNS: Handles public-facing domains and services for global access.

Security

• Internal DNS: Enhances privacy by limiting access to authorized users within the organization.
• External DNS: Requires robust security measures to protect against vulnerabilities like spoofing and DDoS attacks.

Management

• Internal DNS: Typically managed by in-house IT teams who have direct control over network infrastructure.
• External DNS: Often outsourced to third-party providers for scalability and reliability.

Examples

• Internal DNS: Resolves domain names such as ‘server.local’ or ‘app.company.local’ within private networks.
• External DNS: Resolves public domain names such as “company.com” or “shop.example.com.

Advantages of Internal and External DNS

Internal DNS

• Privacy: Hides internal resources from public access.
• Efficiency: Minimizes reliance on external services for local resource access.

External DNS

• Accessibility: Websites and services are accessible to users globally.
• Redundancy: Provides backup systems that can be used in case of network failure.

Common Challenges and Solutions

• Challenge 1: Wrong DNS Record Configuration

Incorrect DNS configurations can disrupt services or pose significant security risks.

Solution: Regularly auditing and documenting the DNS configuration can prevent misconfigurations and security risks.

• Challenge 2: DNS Resolution Lag

Slow DNS query may lead to a bad user experience.

Solution: Use the caching mechanism and CDNs.

• Challenge 3: Security

External DNS is vulnerable to threats such as spoofing and DDoS attacks.

Solution: Use DNSSEC, firewall, and rate-limiting mechanism to secure the DNS infrastructure.

Practical Use Cases

• Internal DNS:

A giant organization deploys Internal DNS for convenience of access to common drives by employees and sensitive applications.

• External DNS

An online shopping platform relies on External DNS to ensure a seamless shopping experience worldwide achieving high uptime and fast load times.

Conclusion

Internal and External DNS are of crucial importance to a network infrastructure, ensuring strength and efficiency. Internal DNS offers protection and ease of access to resources behind the firewall, and External DNS ensures that any public service is accessible and fault-tolerant.

Businesses seeking to optimize their DNS setup can benefit from hosting providers, which offer enhanced performance and robust security. Hosting providers like VPS9 offer robust DNS management solutions, ensuring security, high performance, and reliability for businesses.