DDoS attack – Definition & Prevention

What is a DDoS attack?

The Distributed Denial of Service attack, more commonly known as a DDoS attack, is a serious cyber threat that cyber criminals often initiate to their victims. Through this cyber-attack, they overwhelm the server, system, or network of the victim. The DDoS attack involves numerous devices, also known as a botnet, that send massive amounts of fraudulent traffic to the target. Eventually, the victim gets flooded and unable to operate. 

It is called “distributed” exactly because there are numerous different sources of the attack pointing to the victim. At some point, the limit of resources is reached, and the target is down. The denial of service is completed, and regular users are not capable of reaching and connecting with it.

There are different types of DDoS attacks, and they could be initiated in different ways, yet the goal is always the same – to hit and bring down the target. Generally speaking, each DDoS attack is generated by infecting as many devices connected to a network as possible. Additionally, it could be started from any point in the world and direct massive traffic towards the target to flood it. The sources are compromised and typically are various IoT devices, servers, computers, etc. At first, the target gets sluggish until it drowns completely.

How to prevent a DDoS attack?

DDoS protection

With DDoS protected DNS service, you could strengthen your defense against these malicious attempts called DDoS attacks. It provides a collection of tools that could be very beneficial and ensure the availability of your network, website, or service. In addition, it is far less expensive rather than paying the after-effects of an attack.  

Monitor your traffic.

Usually, online businesses maintain particular traffic patterns. It will be best if you are able to acknowledge them. That way, if there is abnormal activity, you will be capable of distinguishing it. Additionally, with a monitoring service, you will recognize when something about your network is just not right. Thanks to the different types of checks that you could perform, you will know the details about your network and traffic. It is going to help you detect the first DDoS signs before it is too late.

Anycast DNS

Anycast DNS is able to spread the traffic through the entire network of DNS servers in case a DDoS attack is initiated. In addition, if one of the servers is down due to the DDoS attack, the rest of the servers are going to be still up and running. That means they will still answer requests to regular users. The configuration of Anycast DNS is based on several servers holding the same IP address. For that reason, the DNS query of a user is going to continue to search and skip servers that are non-responsive until one of them is available and can provide the answer.

Implement load balancing

It is a beneficial technique that distributes the incoming traffic in a way that prevents overstressing the servers in your network. Providers of quality services offer a great robust network that is perfect for load balancing. That means it is a great opportunity for organizations with big traffic loads. Without a doubt, it is a major advantage when it comes to handling DDoS attacks.

List of DNS records to improve your Email security

These DNS records are going to help you set the grounds for extremely secure and safe email communication. So, let’s start with our short list.

A record

One of the most popular DNS records is the A record, also known as an Address record. It points a domain name to its corresponding IP address (IPv4 address). Its purpose is fundamental. In addition, it shows that the particular domain name is associated with that IP address. However, it does not direct the mail servers, and they wouldn’t know where they should send email messages.

MX record

MX record, or Mail exchanger record, is one of the most popular DNS records. Its main purpose is to show which is the mail server responsible for receiving email messages for the particular domain name. It is important to note that, in case there is a mistake in the configuration of your MX record, or it does not exist at all for your domain name, you won’t be capable of receiving email messages. Therefore, if you desire to have proper receiving mail service, you should definitely set an MX record and be really careful.

PTR record

The Pointer record, or simply for short PTR record, is another essential type of DNS record for your email and email security. Its purpose is to link an IP address (IPv4 or IPv6) to its corresponding domain name. Its goal is absolutely the opposite compared to the A record. It is used to provide trust and confirmation that the particular domain name (hostname) is actually related to the specific IP address. Therefore, it is considered an essential part when you want to establish properly working outgoing mail servers. In case you do not have such a DNS record or you have made a mistake in the configuration of it, the emails you send are going to be marked as spam messages and rejected right away. That is something nobody wants. Therefore you should be aware and set everything correctly.

SPF record

The SPF (Sender Policy Framework) record is a simple TXT record that provides information with a list of all the IP addresses that are allowed to send an email message on behalf of your domain name. Thanks to it, the recipient’s mail server is able to check and verify that the email is actually coming from your domain. It helps prevent DNS spoofing and phishing attacks.

DKIM record

DKIM (DomainKeys Identified Mail) record is another TXT record that serves for email authentication. It allows the recipient’s server to check if the sender is actually the one that is claiming to be and prevent receiving a message from a forged sender. It is really valuable for detecting and stopping email spam and phishing.

Thanks to the provided encryption key and digital signature, it is able to verify that the message was not falsified or modified. Additionally, it improves the security of your email deliverability.

DMARC record

DMARC (Domain-based Message Authentication, Reporting, and Conformance) record is also a TXT Record published for a domain name. It regulates what happens if an email fails the authentication. Together with the SPF record and DKIM record, it sets strong email security.

List of DNS terms that every administrator should know

Here’s a quick rundown of the most useful DNS terms. Learning the complex structure of the Domain Name System as a beginner can be extremely frustrating. But, if we start explaining, everything will become much more straightforward and make more sense.

Domain Name System (DNS)

The Domain Name System, or DNS, is a critical component of the Internet. It’s a global naming database that converts internet domain names to IP addresses (Internet Protocol). DNS is a multi-level hierarchical system that is decentralized. Humans no longer need to remember long and complicated numbers (for example, 213.45.178.32) in order to access and explore every website thanks to this technology. Instead, visitors can type the domain name directly into their browser and go to their selected web page.

Dynamic DNS

Dynamic DNS is the second term in our list of DNS terms. Dynamic DNS (DDNS) has the advantage of automatically updating and changing the host’s IP address.

The A or AAAA DNS entries in classical DNS connect the domain name to the IP address. Dynamic DNS ensures that the user may still access the domain name even if the IP address is changed by the ISP. It is a really easy-to-use solution that also happens to be quite helpful.

Domain name

Another really important term is the domain name. It is a line of text used to map an IP address. We use it to visit websites by writing memorable and straightforward names rather than their numerical addresses, known as IP addresses. For example, instead of 213.45.178.32, we type example4domain.net. So the domain name here is example4domain.net.

IP address

The Internet Protocol (IP) uses an identifier called an IP address to name hosts on the Internet. IANA creates and assigns each IP address, which is completely unique. Furthermore, they are a prerequisite for devices to communicate and exchange information over a network. Today we divide the IP addresses into two categories: IPv4 and IPv6.

Example for IPv4 – 213.45.178.32
Example for IPv6 – 50f1:dc4:0:0:0:ffff:d52d:b220

DNS records

Let’s continue with the next term – the DNS records. They are text files that contain information about the Domain Name System. Every domain has a different amount and variety of DNS records. In addition, they represent the domain’s many entities and settings. For example, the most popular records are – SOA, A, PTR, MX, etc.

DNS query

The process of finding the IP address (an A record or an AAAA record) or different DNS records of a domain we known it as a DNS query. For example, when a customer requests information, it creates a DNS query.

DNS server

And the last important term on our list is the DNS servers. They are split into two categories: authoritative name servers and recursive name servers.

  • Authoritative name servers keep track of a particular zone’s zone file. Furthermore, they are the only ones who can respond to DNS queries. The root server, TLD server, and authoritative name server for a certain domain are examples of such servers.
  • The objective of recursive name servers is to collect the DNS query from the user and then search for the required information. To do so, these servers pass through a series of servers until they get the solution. Consider them to be the intermediary between users and authoritative name servers.

Conclusion

DNS is a multi-component system that aims to make the Internet user experience more pleasant. To sum up, you can now confidently state that you are conversant with the basic DNS terms. They are the basis upon which everything else is built.