What is Anycast DNS?

Anycast DNS is a network addressing and routing technique in which a single IP address is assigned to multiple servers distributed in different geographical locations. It is a method used to improve the performance and reliability of DNS (Domain Name System). 

With Anycast DNS, when a user requests a website, the DNS query is directed to the nearest available server based on network topology, latency, and other factors. As a result, Anycast DNS provides redundancy, load balancing, and high availability.

Unicast vs Anycast DNS Routing

When discussing DNS routing methods, it’s essential to compare Anycast DNS with the traditional Unicast DNS to understand their differences and advantages fully.

Unicast DNS is known as the more traditional form of DNS routing, where each DNS server has a unique IP address. When a DNS query is made, it is routed to a specific server, which has been assigned to handle DNS requests. While Unicast DNS is simple and effective for many applications, it has limitations in scalability, speed, and redundancy. The DNS response time can vary significantly depending on the user’s distance from the server, which can also become a single point of failure if the server goes down.

Anycast DNS uses a single IP address across multiple servers distributed globally. This setup allows a DNS query to be routed to the nearest server in terms of network latency, making it significantly faster and more reliable than Unicast DNS. Anycast DNS provides redundancy and load balancing because if one server fails, the DNS query will automatically reroute to the next closest server. It is especially beneficial for handling large volumes of traffic and defending against DDoS attacks, as the traffic is distributed among multiple nodes rather than directed at a single server.

How does Anycast DNS work?

Anycast DNS uses a group of servers that hold the same IP address rather than having a single DNS server to which all DNS queries go. This results in faster response times and increased reliability, as requests are automatically directed to the closest server

Here are the simple steps involved in how Anycast DNS works:

1. Multiple DNS servers are set up across different geographic locations, each having the same IP address.
2. When a user makes a DNS query for a domain name, the query is sent to the nearest DNS server.
3. The DNS server receiving the query then responds with the IP address of the requested domain name.
4. The user’s device then uses this IP address to establish a connection with the server hosting the domain.
5. If the nearest DNS server is unavailable due to any reason, the query is automatically redirected to the next nearest available DNS server.

Advantages

Anycast DNS is a highly beneficial solution that offers numerous advantages, including the following:

• Anycast is easy to configure. You have just one IP that is assigned to every server, no matter where they are in the world. In more traditional DNS solutions, you would have to configure for every location separately.
• High availability. As we said before, the router will redirect the user to the closest server, but if the server is down, it will simply redirect to one of the rest. They all have a mirror image of the same DNS records, if one is down, the closest next will get the load. The users won’t even notice it.
• Scaling. Anycast DNS is very easy to put in practice. Imagine you are getting too much load on a particular server, what do you do? You just deploy one more server in the area where you need it. It is easy to set it up, and you can do it very quickly. This is one of the common ways how we are expanding our Anycast network.
• Enhanced security. Anycast DNS can help mitigate Distributed Denial of Service (DDoS) attacks by distributing the traffic across multiple servers, making it harder to overwhelm a single server.
• Load balancing. Anycast DNS distributes requests evenly among servers, preventing overload and ensuring load balancing and optimal use of resources.

Anycast DNS network by ClouDNS

You can take advantage of the Anycast technology with each of our Premium DNS, and DDoS protected DNS plans. You will have access to 50+ Points of Presence (PoPs) around the world. There are real hardware devices in each one. These points are distributed in a way to provide fast connectivity to everybody. It also serves as a load balancer to reduce the stress on a single domain server. In the case of DDoS protected DNS plans, you can resist a strong attack by distributing the traffic. 

With ClouDNS, you can use a route monitoring at each PoP. It analyzes the routes and provides the optimal path. Such a system lowers the downtime dramatically. If one server is down, the request is going to another server without extra complications. ClouDNS provides the highest SLA for each location. 

We also provide 24/7 Live Chat support. Our technical team is here to help you if you have any questions regarding our services.

To take advantage of our Premium Anycast DNS service, just go to our page and choose the best plan for you. Our Anycast network consists of 50+ Data Centers on six continents, and we also offer Anycast DDoS protected DNS servers and Anycast GeoDNS servers.

Think about your needs, and if you are not sure what to choose, you can always contact our customer service for help.

Premium Anycast DNS service - Try for free

Conclusion

In conclusion, Anycast DNS is a powerful technology that can help improve website performance, availability, and security. Operating with a network of servers spread across multiple locations allows users to connect to the server closest to them, reducing latency and improving website response times. Additionally, it can help protect against DDoS attacks by spreading the traffic. Whether you’re running a small website or a large-scale application, Anycast DNS can help ensure that your users have a fast, reliable, and secure experience. It is definitely worth considering as a valuable addition to your infrastructure.

The post What is Anycast DNS and how does it work? appeared first on ClouDNS Blog.

What are the DDoS attacks

Cybercriminals are hijacking many random connected devices around the world. The already corrupted devices are called botnets, it is a network that is waiting for instructions from the person in control. The hacker can instruct them to generate traffic to a specific target. The massive number of those devices cripples the defense of the target and brings it down.

Spamhaus 2013

Back in 2013 this was the biggest attack of its time. The website of anti-spam company Spamhaus was down on 18.03.2013 due to a large layer 3 attack. Their servers couldn’t manage the load. The attack was around 75Gbps and back then this was unimaginable (currently there are some with more than 600Gbps). They manage to stop it by signing for Anycast service.

BBC DDoS Attack 2015

A few years ago, on October 21st, 2016, the DNS provider Dyn was struck by a massive DDoS attack. Their servers were down, and for some time, big websites that they were hosting like Amazon, Netflix, Twitter, Reddit and more were out. The culprit of the attack was a botnet called Mirai which was made mostly from IoT devices. The attack had a cascading effect on internet services globally, drawing attention to the vulnerabilities inherent in centralized DNS providers and spurring investment in DDoS mitigation technologies.

Dyn DDoS attack 2016

A few years ago, on October 21st, 2016, the DNS provider Dyn was struck by a massive DDoS attack. Their servers were down, and for some time, big websites that they were hosting like Amazon, Netflix, Twitter, Reddit and more were out. The guilty of the attack was a botnet called Mirai which was made mostly from IoT devices.

Kerbs on Security 2016

In September 2016 just before the Dyn accident, there was another involving the Mirai botnet. The attack was very strong at around 665 Gbps, but that to the Kerbs’s security, they manage to resist it.

The Mirai botnet responsible for the attack was especially alarming for its utilization of Internet of Things (IoT) devices like cameras and routers. This marked one of the first times a botnet had so effectively leveraged commonly used household devices to orchestrate a large-scale DDoS attack.

Blizzard DDoS attack 2017

If you are a gamer, you probably know Blizzard Entertainment, the brand behind Overwatch, World of Warcraft, StarCraft, and Diablo. This company has experienced many attacks over the last years. Most noticeable was in August 2017. Many gamers were unable to connect to their server and play. These attacks are damaging the image of the company and the satisfaction of their clients.

Memcached attacks of March 2018

March was a horrible month. We saw new attacks with a larger than ever before scale. There were two that set a record, the one that hit Arbor Networks with 1.7Tbps traffic and the other that hit GitHub with 1.35Tbps a few days earlier. They both exploited the UDP port 11211. The UDP doesn’t use verification and that is the reason this was possible.

DDoS amplification attacks by Memcached

The different attacks of 2019

In 2019 we didn’t see huge attacks with +1Tbps power, but it wasn’t safe either. 

Yes, there were some strong attacks of around 0.5 Tbps, but we paid attention more to the number of packets per second. In this kind of attack, the criminals do a little work, and the target does a lot of work. This is why they are called asynchronous. The attackers send small packets and receive big ones. The processing occupies the target’s resources. 

Clients of Imperva had a rough start of the year. First, a strong attack of 500 million packets a second in January. It was considered one of the largest PPS (Packets Per Second) attacks known.

Later, on the 30th of April 2019, another client of theirs got attacked with 580 million PPS.

In September 2019, there was another strong attack that was targeting Wikipedia. The popular site didn’t provide information about the magnitude of the attack, but it was down for several hours on different continents.

The AWS Attack 2020

Amazon Web Services (AWS) fell prey to a DDoS attack in February 2020, which peaked at 2.3 terabits per second. The attack was of the Connectionless Lightweight Directory Access Protocol (CLDAP) Reflection type, a common DDoS attack method that amplifies the traffic. Despite the intensity, Amazon successfully mitigated the attack, preventing any significant interruption to its services.

Cloudflare Attack 2020

In August 2020, Cloudflare, a leading DDoS mitigation service, experienced a significant DDoS attack itself. Peaking at 754 million packets per second, it became one of the largest PPS-focused DDoS attacks in history. Remarkably, Cloudflare was able to thwart the attack in seconds using automated systems. However, the incident underscored the evolving complexity of DDoS attacks, showing that even cybersecurity specialists are not immune.

2023 Trends

What can we expect this year? 

• Attacks with a smaller bandwidth, but intense with a high PPS number. The cybercriminals are changing their strategies.

• Increase in the duration of the attacks. Some, they can go for weeks. DDoS protection solutions should be able to withstand longer than before.  

• More sophisticated attacks. It is not just about the volume anymore. For example, the exploit can happen through a different port. 

• More botnets are emerging. There is already a new version of Mirai, new botnet Cayosin, and the IoT number of devices is increasing, and with this, the number of botnet devices.

According to Cisco’s projections, the global landscape for DDoS attacks is expected to witness a significant escalation, with the number of attacks doubling to approximately 15.4 million by 2023. This alarming surge underscores the growing threat of cyberattacks and emphasizes the imperative for organizations to fortify their cybersecurity measures to safeguard against this evolving menace. Since 2018, DDoS attacks have become increasingly prevalent, highlighting the pressing need for proactive defense strategies in the digital realm.

Source: Cisco Annual Internet Report, 2018–2023

How to protect from DDoS attacks?

You can use a DDoS protected DNS plan. Such a plan will include different DDoS protected servers and many Anycast locations. This will do a load balancing that will help you reduce the traffic and spread it to different servers. This way the intense wave of traffic can be reduced and your servers can withstand the DDoS attack.

Protect from DDoS attacks!

Conclusion

The DDoS attack won’t stop, nor will they be lighter. If your business demands your website to be up 100% of the time, you better be prepared with the right security measures.

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