# DNS vs Dynamic DNS vs Anycast DNS

While all three terms involve domain name resolution, they operate at distinct layers of the DNS ecosystem.\
Understanding these differences is essential for designing **resilient, globally distributed, and latency-optimized architectures**.\
Within **Medianova’s DNS platform**, standard authoritative DNS manages domain-to-resource mappings, while **Anycast DNS** provides geographically distributed resolution for speed and redundancy.

### **Standard (Authoritative) DNS**

**Purpose:**\
Maps domain names to static resource records such as IP addresses, MX endpoints, or CNAME targets.\
Authoritative DNS acts as the single source of truth for each zone.

**Characteristics:**

* Deterministic lookups based on record type (A, AAAA, CNAME, MX, etc.)
* Configurable TTL determines caching duration
* Managed through the Medianova Control Panel or API
* Suitable for stable, production environments

**Medianova Context:**\
Medianova provides **authoritative DNS zones** for each CDN Resource and Redirect domain, ensuring consistent propagation and versioned configuration control.

### **Dynamic DNS (DDNS)**

**Purpose:**\
Automatically updates DNS records when an endpoint’s IP address changes — common in residential or small-scale deployments.

**Characteristics:**

* Client agents detect IP changes and push updates to DNS servers
* Records use low TTL values for rapid refresh
* Suitable for IoT, VPNs, or home networks

**Medianova Context:**\
Dynamic DNS is **not typically required** in Medianova’s enterprise CDN infrastructure, where IPs are stable and traffic routing is handled at the CDN and Anycast layers.\
However, it may be useful for **internal monitoring or temporary staging zones** that rely on dynamic endpoints.

**Limitations:**

* Not designed for production CDN workloads
* No guarantee of global propagation consistency
* Dependent on third-party DDNS clients

### **Anycast DNS**

**Purpose:**\
Anycast is a **network-level routing strategy** used to distribute DNS resolution across multiple geographic nodes that share the same IP address.\
BGP automatically directs the resolver to the node with **the most optimal network path**, not necessarily the physically nearest one.

**Characteristics:**

* Same IP address announced from multiple data centers
* Network-proximity routing for lower lookup latency
* Seamless failover during regional or network-level outages
* High resilience against volumetric attacks (DDoS mitigation)

**Medianova Context:**\
Medianova operates **Anycast authoritative nameservers** (`ns1.medianova.com`, `ns2.medianova.com`) to ensure:

* **Low-latency query responses** across global regions
* **Automatic route failover** in case of node or path degradation
* **Consistent propagation** of DNS zone updates

Anycast is the backbone of **Medianova DNS reliability**, enabling faster resolution for CDN, Redirect, and CNAME requests.

### **Comparison Summary**

| Feature                      | Standard / Authoritative DNS          | Dynamic DNS                    | Anycast DNS                          |
| ---------------------------- | ------------------------------------- | ------------------------------ | ------------------------------------ |
| **Purpose**                  | Map static domains to records         | Auto-update changing endpoints | Distribute resolver traffic globally |
| **Update Method**            | Manual or API                         | Client-triggered               | Network-level (BGP)                  |
| **Primary Use Case**         | Websites, CDN resources, mail servers | Remote access, IoT             | Global, low-latency DNS              |
| **Caching Policy**           | TTL-based                             | Very low TTL                   | TTL-based with regional caching      |
| **Reliability Scope**        | Depends on single authoritative zone  | Limited to single endpoint     | Multi-node redundancy                |
| **Medianova Implementation** | Core DNS management system            | Optional for dynamic staging   | Active Anycast DNS backbone          |

### **When to Use Each Type**

| Scenario                            | Recommended Approach | Medianova Feature             |
| ----------------------------------- | -------------------- | ----------------------------- |
| Stable production domains           | Authoritative DNS    | CDN Resource zone management  |
| Changing IP endpoints               | Dynamic DNS          | External DDNS (if required)   |
| Global high-availability resolution | Anycast DNS          | Medianova Anycast Nameservers |