Core Differences

Anycast and Unicast DNS deployments operate fundamentally differently. Anycast distributes queries across multiple servers sharing a single IP address across various locations, while Unicast routes all traffic to one server with a unique IP address.

Performance and Reliability

Anycast advantages:

• Reduces latency by routing queries to the nearest server
• Provides automatic redundancy and built-in failover
• Traffic automatically reroutes if a node fails

Unicast characteristics:

• Routes all traffic to a single server
• Performance depends on user proximity to that server
• Service interruptions occur without alternate resolver configuration

Key Feature Comparison

• Traffic Distribution: Anycast routes to the nearest or optimal server; Unicast routes to a fixed single server.
• DDoS Protection: Anycast distributes load across many servers; Unicast is more vulnerable to targeted attacks.
• Failover: Anycast provides automatic rerouting to available nodes; Unicast requires manual client reconfiguration.
• Geographic Coverage: Anycast is ideal for global infrastructure; Unicast works best for single-region deployments.
• Scalability: Anycast is easily expandable; Unicast is limited by single-server resources.

When to Choose Anycast

Choose Anycast if you need:

• Global operations with high availability
• Automatic failover and load balancing
• Protection against DDoS attacks
• Content filtering and security solutions

When to Choose Unicast

Choose Unicast if you are:

• Operating in a localized area
• Serving a small-to-medium enterprise
• Requiring straightforward setup with minimal maintenance
• Cost-conscious with lower threat exposure

Implementation Requirements

Anycast requires:

• BGP routing and ASN management
• Health checks and monitoring
• Multiple physical or cloud servers

Unicast requires:

• One DNS server and public IP
• Minimal routing considerations
• Basic resolver configuration

CleanBrowsing's Approach

CleanBrowsing offers both options: a global Anycast network across 60+ data centers for standard users, plus customizable Unicast deployments for enterprises and WiFi integrators requiring greater control.