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What is DNS Flood and how to prevent it.

ItsVaness_

24.04.2023

DNS (Domain Name System) Flood is a type of Distributed Denial of Service (DDoS) attack that can cause a server or a network to become overwhelmed and unavailable to legitimate users. In a DNS Flood attack, the attacker sends a large volume of DNS requests to a targeted server or network, consuming all available resources and making it unable to respond to legitimate requests. In this blog, we will discuss DNS Flood attacks in detail and provide some tips on how to prevent them.

How DNS Flood Attacks Work

DNS Flood attacks work by overwhelming a DNS server with a large number of requests that it cannot handle. When a user enters a URL in their web browser, the browser sends a request to a DNS server to convert the domain name into an IP address. The DNS server then responds with the IP address, which the browser uses to connect to the website. In a DNS Flood attack, the attacker sends a large number of fake DNS requests to the targeted DNS server, which can result in the server becoming unresponsive.

Preventing DNS Flood Attacks

There are several steps that organizations can take to prevent DNS Flood attacks. Some of the most effective measures include:
1) Implementing DNS Rate Limiting: DNS rate limiting is a technique that limits the number of DNS requests that a server can receive from a single IP address. By implementing rate limiting, organizations can prevent attackers from overwhelming their DNS servers with a large number of requests.

2) Configuring Firewalls: Firewalls can be configured to block traffic from known malicious IP addresses. This can help prevent attackers from accessing the network and launching DNS Flood attacks.

3) Monitoring DNS Traffic: By monitoring DNS traffic, organizations can identify unusual patterns and quickly respond to potential DNS Flood attacks. DNS traffic monitoring can also help organizations identify the source of an attack and take appropriate action.

4) Using Anycast DNS: Anycast DNS is a technique that distributes DNS servers across multiple geographic locations. This can help prevent DNS Flood attacks by spreading the load across multiple servers, making it more difficult for attackers to overwhelm any single server.

5) Keeping Software Up to Date: Keeping DNS software up to date is important in preventing DNS Flood attacks. Software updates often include security patches that address vulnerabilities that could be exploited by attackers.

Conclusion
DNS Flood attacks can cause significant damage to organizations by making their networks and services unavailable to legitimate users. However, by implementing the steps outlined above, organizations can significantly reduce their risk of falling victim to DNS Flood attacks. By taking a proactive approach to network security, organizations can help protect themselves against this and other types of cyber attacks.