What is anycast?

Anycast is a network addressing and routing method in which incoming requests can be routed to various locations or “nodes.” In the context of a content delivery network

(CDN), anycast typically routes incoming traffic to the nearest data center with the capacity to process the request efficiently.

Understanding anycast

Anycast is a technique for distributing incoming traffic across multiple data centers within a CDN. When a user requests a website, the request is directed to the nearest data center that can efficiently process it. This selective routing ensures the content is delivered faster, reducing latency and improving the overall user experience.

In the context of CDNs, Anycast is particularly useful for handling high traffic volumes, network congestion, and DDoS attacks. By distributing traffic across multiple data centers, anycast ensures that no single server or data center becomes overwhelmed, preventing service interruptions and maintaining the availability of content.

How anycast works

Anycast routing operates by associating multiple data centers with a single IP address. When a request is received, the anycast network determines the optimal data center to process the request based on various factors, such as network latency and proximity. The goal is to choose the data center that is closest to the requester, minimizing the distance the data needs to travel.

Benefits of an anycast network

Using an anycast network offers several benefits, especially in the context of CDNs. Here are some advantages:

Improved performance and latency

Anycast routing improves performance and reduces latency. Directing traffic to the nearest data center minimizes the distance data needs to travel, resulting in faster content delivery. This is particularly important for websites and applications that require real-time data updates or have interactive elements.

Load balancing and scalability

Anycast enables load balancing across multiple data centers. Instead of overwhelming a single server or data center with high traffic volumes, requests can be distributed across available data centers, each equipped with servers capable of processing and responding to incoming requests. This load-balancing capability enhances scalability, ensuring that the network can handle increasing traffic demands without service interruptions.

Resilience and DDoS mitigation

One of the advantages of Anycast is its resilience against DDoS attacks. DDoS attacks involve overwhelming a target server or network with massive traffic, rendering it inaccessible to legitimate users. Anycast mitigates this risk by distributing the attack traffic across multiple data centers. Suppose the capacity of the anycast network exceeds the attack traffic. In that case, the attack can be effectively absorbed, ensuring the availability of services.

Read more: What is a DDoS attack? 

Anycast and DDoS mitigation

DDoS attacks threaten online services, and CDNs are often targeted due to their function in content delivery. When a DDoS attack occurs, various mitigation tools filter out some of the attack traffic. Anycast then distributes the remaining attack traffic across multiple data centers, preventing any one location from becoming overwhelmed.

According to Cloudflare, “In most DDoS attacks, many compromised ‘zombie’ or ‘bot’ computers are used to form what is known as a botnet. These machines can be scattered around the web and generate so much traffic that they can overwhelm a typical Unicast-connected machine.

A properly Anycasted CDN increases the surface area of the receiving network so that the unfiltered denial-of-service traffic from a distributed botnet will be absorbed by each of the CDN’s data centers. As a result, as a network continues to grow in size and capacity it becomes harder and harder to launch an effective DDoS against anyone using the CDN.”

Related: What is a botnet?

FAQs

What are the potential risks associated with using anycast in healthcare under HIPAA?

• Misrouting risks: If anycast configurations are not properly managed, data might be routed to unintended servers, potentially exposing ePHI to unauthorized access.
• DDoS attack amplification: Although anycast can mitigate DDoS attacks by dispersing traffic, improper implementation could amplify such attacks and disrupt healthcare services.
• Lack of access control: Ensuring that anycast servers only route to HIPAA-compliant locations is crucial; otherwise, ePHI could be exposed to regions or servers with inadequate security controls.
• Non-compliance penalties: If anycast configurations lead to unauthorized access or breaches of ePHI, healthcare organizations could face significant penalties for violating HIPAA regulations.
  
  

How can healthcare facilities implement anycast securely to maintain HIPAA compliance?

• Using authorized data centers: Ensuring anycast routing only directs traffic to HIPAA-compliant, authorized data centers with adequate security controls.
• Configuring access controls: Applying strict access controls and ensuring that only authorized personnel have access to anycast routing configurations to prevent misrouting of ePHI.
• Monitoring traffic and load distribution: Regularly monitoring traffic patterns and load balancing to detect and address any unusual behavior or potential security threats.
• Establishing redundancy and failover measures: Using anycast to route traffic across multiple data centers to ensure continuous access to ePHI, even if one server is unavailable.
• Implementing DDoS protection: Using anycast's distributed routing to mitigate DDoS attacks and maintain HIPAA-compliant service availability.

See also: HIPAA Compliant Email: The Definitive Guide