What is DNSSEC?

DNSSEC is a security extension that uses a combination of public and private keys to sign data and verify the authoritative server.

DNSSEC is a cryptographic solution for domain authentication. 

With it, even if a recursive server was poisoned by hackers, it won’t send the visitors to a shady website where their personal data and bank information can be stolen. The DNSSEC must be applied at each step, from the root zone to the domain. The root zone will have a key for the .com and the .com will have for the EXAMPLE.com. DNSSEC is a chain of trust that needs to be verified on each point.

How DNS Works and the Role of DNSSEC

We have already talked about how DNS works. Briefly explained, it is a system that facilitates our lives by translating domain names to their IP addresses. This way, visitors don’t need to remember IP addresses and just write the name of the domain. In the DNS, users’ requests go through different recursive servers until it reaches the root zone where the IP addresses are stored.

However, when DNS was created, security wasn’t a major concern. This left DNS vulnerable to attacks such as DNS spoofing (or cache poisoning), where a hacker manipulates DNS records to redirect users to malicious sites. DNSSEC was developed to secure the DNS without completely rebuilding its core architecture.

The Importance of DNS Security

The DNS Security should not be neglected. Especially when we think about how many people connect their devices and use them on unsecured public Wi-Fi networks. Their DNS traffic could go to a poisoned DNS resolver that has modified DNS records. A modified DNS record could lead to a similar or exactly the same looking site that is there to get the person’s personal data, including bank data. The victim won’t even notice there was a problem until it is too late and all thanks to the weak DNS security that a non-DNSSEC solution offers by default. 

When you apply DNSSEC for your domain, all those users who are using public Wi-Fi networks or private ones will be safe from such scams. Their web browser will recognize the DNS record that is not signed correctly with DNSSEC, and it will drop it. 

The DNSSEC is proof of original and non-manipulated DNS records that secures DNS and fixes its flaws. It is cryptographically protected and secure.

How does DNSSEC work?

DNSSEC works by adding digital signatures to DNS records using public-key cryptography. Here’s a simplified breakdown of how it works:

1. Public and Private Keys: DNSSEC uses a pair of cryptographic keys – one public and one private. The private key is used to generate digital signatures for DNS data, and the public key is used by DNS resolvers to verify that the signatures are valid.
2. Signing DNS Records: When DNSSEC is enabled for a domain, its DNS records are digitally signed using the domain’s private key. This means that if anyone tries to tamper with the records, the signature will no longer match, and the change can be detected.
3. Chain of Trust: DNSSEC uses a hierarchical trust model. On top of this trust is the DNS root zone, which is managed by trusted organizations. Each level of the DNS hierarchy (from the root to TLDs like .com, down to individual domains) is responsible for signing the records at the next level down. For example, if you own a domain like “example.com”, your domain’s signatures are verified by the “.com” zone, which in turn is verified by the root zone.
4. Resolvers and Validation: When a DNS resolver queries a DNSSEC-enabled domain, it not only receives the usual DNS data (such as the IP address) but also the associated digital signatures. The resolver then uses the public key associated with the domain to verify the signature. If the signature is valid, the resolver can be confident that the DNS data hasn’t been modified.

Key Components of DNSSEC

There are a few critical terms and components to understand when discussing DNSSEC:

1. DNS Record Types: DNSSEC adds several new DNS records to achieve signature validation.
   • RRSIG: The digital signature associated with a particular set of DNS records.
   • DNSKEY: This record contains the public key used to verify RRSIGs.
   • DS Record: A delegation signer record that authenticates the connection between a domain’s DNS zone and its parent zone. It contains a hash of the DNSKEY record, which allows resolvers to verify the authenticity of DNS responses and ensure the integrity of the domain’s DNS data.
   • NSEC/NSEC3: It is a pointer to the next secure record name in the zone.
2. Resource Record sets (RRsets): They gather the same type of DNS records, such as A, AAAA, and MX. The RRsets help to reduce the complication of verifying single records.
3. Zone-Signing Keys (ZSK): These keys are used by the DNS zone operator to sign individual DNS records (RRsets) within the zone. The private ZSK signs the RRsets and saves them in the form of RRSIG records. The public ZSK is published in the form of DNSKEY to validate these signatures.
4. Key-Signing Keys (KSK): The KSK is used to sign the DNSKEY record, which includes the public ZSK. The private KSK signs both the KSK and the ZSK, ensuring trust in the zone’s cryptographic keys.

What does DNSSEC mean for the end users?

Enabling DNSSEC will guarantee that the users will access the right website, not a fake copy. It doesn’t remove the need of a SSL certificate for data encryption and further protection of users’ data, but it secures the otherwise unsecured DNS.

Who Needs DNSSEC?

The simple answer is anyone with a domain name! However, some types of websites benefit the most from this solution:

• eCommerce Sites: Protecting customers’ financial information and preventing phishing attacks is critical. DNSSEC ensures that users connect to the correct server and are not misled by a fake site.
• Financial Institutions: Online banking services are frequent targets of DNS attacks, especially due to the sensitive nature of their transactions. Implementing DNSSEC is crucial to protecting both customers and the institution from fraudulent activities.
• Healthcare Organizations: With the rise of online health services and medical records, healthcare websites need to ensure the privacy and accuracy of patient data. DNSSEC adds a layer of protection essential for safeguarding personal health information.
• Enterprises: Large corporations often have multiple domains, subdomains, and services hosted online. DNSSEC prevents DNS hijacking that could damage the company’s reputation and customer trust.

Even if you run a small blog or a simple business website, this service ensures your domain won’t be exploited for malicious purposes. It’s a valuable tool for maintaining the security and integrity of any online property.

ClouDNS and DNSSEC

ClouDNS offers DNSSEC both for Primary and Secondary DNS for each of our paid DNS plans. The DNSSEC is compatible with non-DNSSEC resolvers too. This means that if you enable it, The DNS will continue to function without problems even if the resolver(s) doesn’t support DNSSEC. Having a secure DNS is easy.

Benefits

Some of the key benefits include the following:

• Improved Security: It ensures the authenticity and integrity of DNS responses by digitally signing DNS data, protecting against attacks like DNS spoofing and cache poisoning.
• Data Integrity: It guarantees that the DNS data has not been tampered with during transmission, ensuring reliable communication.
• Trust Establishment: DNSSEC creates a chain of trust from the root DNS servers down to individual domains, enhancing overall trust in internet services.
• Prevents Redirection: It helps prevent users from being unknowingly redirected to malicious websites by ensuring the validity of DNS responses.

Cons of DNSSEC

As you could guess, there are some negatives with it too. Apply it correctly will create more records. Furthermore, it will increase the size of the DNS responses.
Still we recommend the use of DNSSEC. It is not hard to apply, it will provide an extra security and save you many problems with your clients.

Conclusion

DNSSEC plays a vital role in keeping the internet secure. As cyber threats like DNS spoofing, man-in-the-middle attacks, and cache poisoning are becoming common, protecting your DNS is essential. By using this service, you protect the integrity of your domain and ensure that your users can always reach your legitimate website. No matter the size of your online presence, whether it’s a personal blog or a large company, DNSSEC offers an important layer of protection that helps keep your domain secure and trustworthy.

The post DNSSEC, the DNS Security extension appeared first on ClouDNS Blog.

The history of PowerDNS

PowerDNS was first introduced in 1999 by Bert Hubert with the task to write load balancing software for V3 Redirection Services for “come.to”, “browse.to“, and “go.to”. Back then, it was still a close-source. After the Dot Com Bubble, the company needed to re-think their future and released the software as an open-source. It started to provide commercial services from 2005 and in 2015 became a part of Open-Xchange.

It quickly gained attention for its unique architecture and capabilities. Unlike traditional DNS servers that store data in zone files, PowerDNS uses databases like MySQL, PostgreSQL, and SQLite to store DNS information, making it more flexible and easier to integrate with existing infrastructure.

One of the standout features of PowerDNS is its support for multiple backends, allowing administrators to choose the most suitable database backend for their specific needs. This adaptability makes PowerDNS well-suited for a wide range of deployment scenarios, from small businesses to large enterprises.

PowerDNS platform

PowerDNS or pdns is an open-source (GPL) software. It provides software to create authoritative DNS, Recursive DNS, DNS loading balancer, Debugging tools, and APIs to provision zones and records. A complete suite of DNS-related software that you can use for your company.

It provides a flexible, extensible, and high-performance platform for managing DNS. Unlike traditional DNS solutions, PowerDNS is designed with flexibility and adaptability in mind. Therefore, it can be adjusted to answer a wide range of DNS needs, from simple authoritative DNS serving to complex and advanced features.

Authoritative Server

PowerDNS’s Authoritative Server is designed to handle authoritative DNS queries efficiently. It allows domain owners and administrators to manage their DNS zones and DNS records. This includes records like A (address) records for mapping domain names to IPv4 addresses, MX (mail exchange) records for email routing, TXT records for various purposes, including domain verification. PowerDNS’s modular architecture and support for different backends allows administrators to store DNS data in various data sources, such as databases or flat files.

It enables the authoritative DNS service from all popular databases like MySql, Oracle, PostgreSQL, SQLite3, Microsoft SQL Server, LDAP, and text files.

Authoritative Server works with many different scripts like Java, Python, C, C++, Perl, Lua. You can use it for dynamic redirection, spam filter, or real-time intervention.

Recursor (Recursive DNS)

PowerDNS’s Recursor is a component that provides Recursive DNS resolution. It handles DNS queries from clients, gets the necessary DNS information by querying Authoritative servers, and then returns the results to the client. The Recursive DNS is designed to optimize performance by implementing caching mechanisms and managing queries efficiently. It helps achieve faster DNS lookups and improves user experience by reducing latency.

It provides a high-performance Recursive DNS server. PowerDNS Recursor can use multiple processors. Just like the Authoritative Server, it supports various scripts. A good advantage is that it can be reconfigured without downtime.

Dnsdist (load balancer)

Dnsdist is a powerful load balancer that allows administrators to distribute incoming DNS queries across multiple Authoritative servers or DNS resolvers. It ensures the traffic is routed to the optimal servers, which results in delivering excellent performance. 

It can also be configured to implement various filtering and policy rules, such as blocking malicious DNS queries or sending certain types of DNS queries to precise servers. In addition, Dnsdist provides detailed statistics and metrics, which are very helpful for administrators to monitor the health and efficiency of their DNS infrastructure.

Key Benefits and Features of PowerDNS

PowerDNS stands out mainly due to its remarkable benefits and features:

• High Performance and Scalability: PowerDNS is well-known for its exceptional performance. It can handle many queries per second while maintaining low latency. On the other hand, its modular architecture allows scaling and distributing the load across multiple points.
• Flexible Backends: Certainly, its standout feature is its ability to support multiple backend databases simultaneously. The flexibility and modular architecture allow organizations to choose the backend that best fits their existing infrastructure, data management practices, and performance requirements.
• DNSSEC Support: Domain Name System Security Extensions (DNSSEC) enhance the security of DNS by digitally signing DNS data. PowerDNS offers complete DNSSEC support, allowing the use of secure DNS services.
• Dynamic Updates: This feature allows authorized clients to dynamically add, modify, or delete DNS records. It is especially helpful for environments where frequent changes to DNS records are required, such as dynamic IP allocation in ISP environments.
• API Integration: PowerDNS comes with an HTTP-based API that allows seamless integration with other systems. Additionally, the API-based approach simplifies processes like automation, monitoring, and management of DNS services.
• Geo-Redundancy: PowerDNS offers built-in geographical load balancing and failover capabilities. It can direct users to the nearest available server, enhancing both performance and resilience.
• Various Use Cases: It is a proper solution in many different cases, including enterprises managing complex DNS infrastructures, service providers handling large DNS query loads, organizations focusing on DNS security with DNSSEC, and environments requiring automation and integration capabilities.

It is a fantastic tool that also offers instant startup when hosting many domains, different scripts, IPv6 support, use of multi-core (32+ cores) processors, and on top of that, it has low memory requirements.

PowerDNS vs. BIND

When choosing a DNS solution, it’s essential to consider the strengths and features of PowerDNS and BIND.

PowerDNS:

• Flexibility and Performance: PowerDNS supports multiple backend databases (MySQL, PostgreSQL, SQLite), making it highly adaptable for dynamic and scalable environments.
• Advanced Features: It offers DNSSEC, API-based automation, and a modular architecture, allowing seamless integration with existing infrastructure.
• Modern Design: Designed with performance and contemporary needs in mind, PowerDNS excels in handling high query loads efficiently.

BIND:

• Stability and Reputation: BIND has a long-standing reputation in the DNS world for its stability and reliability.
• Extensive Documentation: It has comprehensive documentation and a large user community, making it easier to find support and resources.
• Traditional Setups: Ideal for setups where stability and a proven track record are the primary requirements.

Choosing between PowerDNS and BIND depends on your specific needs. Opt for PowerDNS if you require flexibility, high performance, and advanced features. Choose BIND if you prioritize stability and a well-established solution for traditional DNS setups.

Conclusion

PowerDNS is a great alternative to BIND. It is full of features, and it can provide a quality and secure service. The platform offers a comprehensive suite of tools that serve the various needs of different domain administrators and networking professionals. It is a fantastic solution that highly prioritizes performance and security.

The post What is PowerDNS? – Open-source BIND alternative appeared first on ClouDNS Blog.

DNS Monitoring explained

DNS Monitoring gives you the ability to manage and examine the performance of a DNS server. The main goal is to assist you with detecting server-side and client-side DNS issues. In addition, it guarantees the health of DNS servers by sending a DNS request. You are able to choose different query types depending on the DNS record you want to check, for example, A, AAAA, MX, NS, PTR, or CNAME. Then you specify a required expected response that is compared to the actually received response.

DNS Monitoring has a very important role in your network Monitoring service. Moreover, it ensures the safety and proper connection between the end-users and the website or service that they want to use. It is extremely useful when it comes to the fast detection of unpleasant issues or for recognizing potential security breaches. Additionally, it is helpful for stopping some popular malicious attacks. Thanks to the regular checks, you can effortlessly detect unexpected issues or localize DNS outages. As a result, you can prevent a large negative impact on your website or on the safety of your users that want to reach your services by detecting and resolving the problem fast.

Why is DNS Monitoring important?

The Domain Name System (DNS) is an essential part of the Internet. Yet, it was not designed with security in mind. For that reason, cybercriminals have developed ways to take advantage of its vulnerabilities. Therefore, DNS monitoring is vital for helping you protect your online presence and catch issues before they become significant problems. DNS monitoring gives you the ability to recognize several different DNS errors. The majority of them result from malicious attempts and could be a significant threat to your security. On the other hand, there are also communication flow interruptions. They compromise the functionality of your domain’s DNS resolution process and lower the traffic toward your site.

Configuration Errors

DNS Monitoring can detect errors like incorrect IP addresses and assure that outages are not prolonged. The less time your website or service is down, the less your traffic flow is interrupted. That way, you can maintain and increase your uptime, and every user that wants to reach your website (or service) will have that opportunity without any difficulties.

A configuration error can stop users from reaching your website and make it seem like their internet is not acting correctly. This could drive traffic away from your domain and meddle with your business.

DNS Spoofing (DNS poisoning)

DNS Spoofing, also commonly known as DNS poisoning, is a popular cyber threat that cybercriminals use. Recursive DNS servers hold the hostname data with all related DNS records for a particular amount of time (depending on the TTL). That way, they operate more efficiently because they do not repeat the resolution process for the same IP address. However, it also leads to vulnerabilities.

Cybercriminals insert fraudulent data into the DNS cache on the server, like fake IP addresses. Commonly, that is achieved due to viruses and malware. As a result, the users’ requests are directed to a malicious phishing website, which looks similar to the original one. There they type their sensitive information, such as passwords, credit card details, etc. A lot of people do not even notice that they have been directed to malicious pages. No one wants to put its clients at risk of phishing schemes. Additionally, compromising user information can seriously impact your business.

DDoS and DoS Attacks

Distributed Denial of Service (DDoS) and Denial of Service (DoS) attacks are massive cyber threats that are able to bring down your server. They involve large amounts of fake traffic with the main goal of overcoming your resources and making your website or service unavailable for regular users. It is important to mention that the earlier the attack is detected, the more quickly it can be handled. Therefore, it is best to stop it before the DNS records on the server become weaponized by the cybercriminals.

DNS Tunneling

DNS Tunneling is another cyber threat that attackers commonly use. Typically, DNS servers handle a massive amount of traffic, and there are no security measures regarding the exchanged data packets. DNS Monitoring can help detect tunneling and serve to prevent any further data from being exchanged. This is an essential addition to your existing security measures.

DNS outage

DNS outage does not allow your users to connect and reach your website or service. It is possible to last just several minutes, but it could continue up to several hours or even days. So you can probably imagine how seriously it can affect your business and services. With DNS Monitoring, you can easily find and understand where the issue is coming from and quickly fix it.

How does it work?

You can find DNS monitoring as a part of ClouDNS Monitoring service. It works by regularly checking if the DNS server responds to all DNS queries. With such type of check, you can initiate DNS queries for a desired hostname and query type – A (for IPv4), AAAA (for IPv6), MX, NS, PTR, or CNAME. There are two scenarios that follow once you set your expected response.

• The check is marked UP, when the received response is equal to the required expected one.
• The check is marked DOWN, when the received response is not equal to the required expected one.

The DNS monitoring check validates the conditions of DNS servers by sending a DNS request and comparing the received response with the expected one.

You can also take a look at our article about DNS monitoring Checks!

Why do you need it?

DNS monitoring is necessary because DNS performance is essential to your network, servers, and applications. Thanks to the DNS servers, your website or service works effectively and efficiently, yet they should be monitored for vulnerabilities. In case you neglect their adequate supervision, you may compromise both the security of your business and your clients.

With the ClouDNS Monitoring service, you can keep an eye on your servers and quickly detect any issues. As you know, timing is crucial, so the fast resolving of the issues is going to guarantee the integrity of your servers. So, as a result, everything should continue operating smoothly.

Benefits of DNS monitoring

DNS monitoring is a critical component of any organization’s network management strategy. By monitoring DNS traffic, organizations can proactively identify and address issues before they escalate. Here are some of the main benefits of the implementation of DNS monitoring:

• Improved Server Availability

It can help improve server availability by identifying and resolving issues that can cause downtime or service disruptions. For example, DNS servers can be vulnerable to hardware or software failures, network connectivity issues, and cyber attacks, which can affect the availability of websites and other online services. DNS monitoring services can detect and alert tech teams of problems before they escalate, allowing them to take proactive measures to resolve them.

• Improved DNS Server Troubleshooting

DNS monitoring can help improve DNS server troubleshooting by providing visibility into the DNS infrastructure and the flow of DNS queries. Tech teams can use DNS monitoring tools to identify blockages, misconfigurations, and other issues affecting the performance of the DNS server. The information helps them troubleshoot and resolve issues more quickly, minimizing downtime and service disruptions.

• Faster Detection of Outages

DNS monitoring can be useful for detecting outages faster by providing real-time visibility into the DNS infrastructure. It can alert tech teams about issues, such as DNS server failures or network connectivity problems, as soon as they occur. That way, IT teams can quickly identify the root cause of the problem and take action to restore services.

Monitoring Plan

Comparison with other monitoring techniques

DNS monitoring is a specialized approach focusing on the health and security of the Domain Name System, which is crucial for translating domain names into IP addresses. While DNS monitoring is vital, it’s one part of a broader network monitoring strategy that includes other techniques such as network performance monitoring, application monitoring, and security information and event management (SIEM). Here’s how DNS monitoring compares with other monitoring techniques:

• Network Performance Monitoring (NPM): NPM tools focus on the performance and availability of networks and network components (like routers and switches). While NPM can identify network congestion and hardware failures that indirectly affect DNS services, DNS monitoring directly assesses DNS health, ensuring that domain name resolution processes are working as expected.
• Application Monitoring: This technique focuses on the performance and availability of specific applications. It can help identify issues within an application that may impact user experience but doesn’t directly monitor DNS processes. DNS monitoring complements application monitoring by ensuring that users can reach the applications in the first place.

Security Information and Event Management (SIEM): SIEM systems collect and analyze aggregated log data from various sources to detect and respond to security incidents. While SIEM can identify security breaches that may indirectly affect DNS services, DNS monitoring provides specific insights into DNS-related security threats, such as DNS spoofing or tunneling attacks.

Conclusion

So, now you know what DNS Monitoring is and why it is so important for your security. First, there are different criminal attempts that could be prevented when you keep an eye on your servers. Additionally, it is beneficial for simplifying the process of finding and fixing network issues. Finally, it helps you prepare and not be surprised in such situations.

The post Monitoring your DNS, should you do it? appeared first on ClouDNS Blog.

The Domain Name System (DNS) is often compared to a phonebook, and there are a lot of similarities. It is another type of database. DNS is a global system that we all use on a daily basis when we want to access any website. It contains and distributes information about domain names and their corresponding IP addresses. This way, when we type a simple domain name, our browsers or application will use the DNS to search for its IP address and connect us. The DNS is divided into domains from different levels, and it is managed through DNS zones that are decentralized. An administrator of a higher level can delegate a zone to another under it. For example, when you get a domain name (secondary-level domain like yoursite.com), the higher level .com (TLD) can delegate you the right to manage the zone yoursite.com. You can further delegate responsibility for all subdomains like mail.yoursite.com, ftp.yoursite.com, etc. To manage domain names, you add DNS records, which are a set of instructions related to your domains, hosts, services, and more.

Domain Name System explained

List of DNS terms

Here you have the most important DNS terms that you will need to manage your domain name. First, you can learn the basics of DNS, and later you can expand your knowledge with larger articles that go into greater details on topics like DNS records, DNS features, and processes. 

Domain Name

It’s an identifier of a host, a text line, that servers for mapping to an IP address (a line of numbers like: 46.166.142.62) for easy access to a website. By now, you have typed a lot of different domain names in the URL bar of your browser to reach different websites. Example: cloudns.net

Machines have always searched websites through their IP address. Numbers are the best way for machines to understand each other. But numbers are hard to be remembered by humans. That’s why domain names were created. To have a friendly choice for humans to reach the websites they look for.

IP Address

An Internet Protocol address is another host identifier that is created of a line of numbers divided into groups by periods. Example: 46.166.142.62. IP addresses are needed so devices can connect to networks and communicate using the Internet Protocol (IP).

The set of numbers on every public IP address is mathematically generated and allocated by the Internet Assigned Numbers Authority (IANA). An entity of the Internet Corporation for Assigned Names and Numbers (ICANN).

Basically, IP addresses allow the identification, location, and communication of hosts on a network. Every device uses a unique IP address. This way, the Internet and networks, in general, can distinguish all the websites, routers, connected computers.

Many IPv4 addresses are still in use, but the latest standard IPv6 is growing in popularity.

TLD (Top-level Domain)

Domain names have a hierarchy structure. The top-level domain is one of its parts, and it’s located, reading from right to left, just after the final dot for the root and before the secondary-level domain name. Examples: .com, .gov, .uk, .ru, etc.

Initially, TLDs were created to organize domain names by their purpose, geographical location, field, operation radius. By only reading this part of a domain name, users could also know if a website they visited belonged to a commercial, government, non-profit organization, operating regionally, locally, internationally, and so on.

In the beginning, this use was more strict. In 2010, the Internet Corporation for Assigned Names and Numbers (ICANN) accepted the creation of new, generic, trademark TLDs. Now, TLDs are chosen to obey Marketing objectives too.

FQDN (Fully Qualified Domain Name)

It’s the most complete domain name that hosts can have. It points to the exact location of a domain name in the domain name system (DNS) tree hierarchy. This is expressed through the three parts that shape every domain name: hostname, second-level domain name, and top-level domain name (TLD). Following this structure, here you have an example: www.cloudns.net.

Anycast DNS

Anycast DNS is a traffic routing method where the same IP address is used for multiple nameservers located in different locations. Usually, there are many locations (points of presence) – at least 20 for a well-sized DNS provider. Having a large number of servers makes Anycast DNS resistant to DNS attacks and provides redundancy in general. 

When a client request a domain, the router will direct its request to the nearest nameserver. This will reduce the latency and offer a better experience for the clients.

Dynamic DNS

Dynamic DNS, also known as DDNS, is an automatic method of updating nameservers. The most common use case is to update IP addresses that are contained in A records (IPv4) or AAAA records (IPv6) when a change has occurred. It is particularly useful for CCTV cameras or remote services because with Dynamic DNS, you don’t need to pay for static IP addresses. The IP addresses will change over time, but they will be updated, and you won’t experience problems. After the initial setup process, you don’t need to interact with the settings, and it will continue to function.

DNSSEC

DNSSEC is a security extension that has the goal to protect DNS communication and stop DNS spoofing. It encrypts the DNS communication with a combination of private and public keys. One that the zone administrator uses to sign it and the other for authentication of the origin of the data. What makes it a good protective mechanism is that it is a complete chain of trust. Starting from the root zone down to the TLD zone, the domain zone, and subdomains, each zone above will have the key for the next one. It adds security to the fast DNS process without a significant slowdown.

DNS Server (types)

There are different DNS servers, and each has specific functionality.

Root server. It belongs to the highest level of DNS servers. It’s the authoritative name server for a specific DNS root zone. It points to the TLD of the requested domain name.

TLD server. It’s responsible of specific TLDs (.com, .gov, .uk, .net, etc.). It will point to the exact, authoritative name server that can provide the IP address for the requested domain name.

Recursive DNS server. The server takes the user’s DNS request and looks for the IP address or other information needed for the requested domain name. It will communicate with all the other DNS servers in the hierarchy for getting this information.

Authoritative DNS server. It contains all the DNS records for the zone it’s in charge of. It answers the requests that recursive DNS servers have by providing the corresponding A or AAAA record and the IP address of the requested domain or another DNS record.

Primary authoritative DNS servers. They answer DNS requests, and they store the original zone file. Therefore, DNS records’ modifications can only be made on these servers. 

Secondary authoritative DNS servers. They also respond to DNS requests, but what they store is a copy of the zone file. This copy is not editable at all, only readable. 

DNS Zone

The DNS system has a structure that looks like an inverted tree. It is divided into domain names on different levels. The highest level is the root, after many TLDs, secondary-level domains, and later multiple levels of subdomains. To administrate those domain names, there are DNS zones on each level. The DNS zones are partitions of the Domain Name Space that contain DNS zone files with DNS records for managing. A DNS zone administrator can add or remove DNS records inside the Primary DNS zone.

DNS records

DNS records are simple files that contain text with instructions related to the domain name they belong to. They can link domain names to IP addresses, add instructions for email servers, point to specific services, and much more. The DNS records are hosted inside a host file in a DNS zone. The zone is located inside an authoritative nameserver.

There are many types of DNS records, but the most popular ones are:

A record – Links a domain name to an IP address. 

CNAME record – Forwards subdomains to the domain name.

MX record – Indicates the email servers that should receive emails for the domain name.

TXT record – Multiple verifications and authentication purposes.

NS record – Shows the nameservers for the domain name.

SOA record – Start of authority.

SRV record – Links services to port numbers.

PTR record – The Pointer record links an IP address to a domain name.

The Importance of DNS Terminology

Understanding DNS terminology is crucial for various reasons, including the following:

• Efficient Troubleshooting: Solid knowledge of DNS terms allows IT professionals to diagnose and resolve technical issues more efficiently. Identifying the root cause of problems, such as domain resolution failures or misconfigured DNS records, becomes significantly easier and faster.
• Enhanced Security: Cybersecurity is a top priority nowadays. Therefore, it is best for professionals to understand DNS terminology in order to detect and respond to potential threats. Understanding terms like DNSSEC, DNS spoofing, cache poisoning, and DDoS attacks helps strengthen the security of networks and web services.
• Performance Optimization: Website owners and developers can benefit from understanding DNS terminology to optimize the performance of their online presence. Fine-tuning DNS settings, minimizing TTL values, and ensuring proper DNS record configurations contribute to faster and more reliable website performance.
• Effective Communication: Clear communication within IT teams, especially between developers, network administrators, and support teams, is crucial, especially when they need to communicate complex technical issues. A common understanding of DNS terms allows effective communication and collaboration within teams.
• Domain Management: Individuals and organizations involved in registering and managing domains must be familiar with DNS terminology to make informed decisions. Knowledge of terms like TLDs, registrars, and DNS hosting providers empowers domain owners to navigate the complexities of the domain ecosystem.

Conclusion

This list of basic DNS terms you should know is a good start for exploring the DNS. If you want to learn even more, follow our blog, in which we regularly post new extended articles. Also, don’t miss our Wiki page and YouTube channel.

The post Basic DNS terms you should know (List + Infographic) appeared first on ClouDNS Blog.

DNS explanation

To understand clearly how DNS filtering operates, we need to explain the purpose of the Domain Name System briefly. 

DNS, which stands for “Domain Name System,” converts the names of websites into IP addresses that browsers can recognize. As a result, whenever you visit a website, your browser requests a particular kind of DNS server. This server returns a corresponding IP address after examining the requested domain name. Then, the page can be loaded from there in a split second, providing you full access.

What is DNS filtering?

DNS filtering, or DNS blocking, is a security technique that prevents access to malicious, untrustworthy, or otherwise undesirable domains or IP addresses. When a user attempts to access a web address, the DNS query is compared to a blocklist of undesirable domains or IP addresses. And if a match is found, the domain is not resolved, and access is denied.

How does it work?

It works in a simple way. All DNS queries are routed through a Recursive DNS server (DNS resolver). DNS resolvers that have been specially configured can also act as filters by refusing to resolve queries for specific domains that are tracked in a blocklist, preventing users from accessing those domains. DNS filtering services can also employ an allowlist rather than a blocklist

Let’s say an employee for the organization receives a phishing email. It falls for the trick of clicking a link that takes them to malisiousexample.com. The company’s DNS resolving service, which uses DNS filtering, receives a query from the employee’s computer before it loads the webpage. The DNS resolver will reject the request if the malicious website is listed on the company’s blocklist. This will stop maliciousexample.com from loading and stop the phishing attack.

DNS filtering can ban websites either by IP address or domain name:

• By IP address: The DNS resolver tries to resolve every domain, but the resolver won’t send the result back if the querying device’s IP address is on the blocklist.
• By domain: For some domains, the DNS resolver does not even attempt to resolve, or look up, the IP addresses.

What does having a secure DNS server mean?

A secure DNS server is a DNS resolver that filters unsafe or restricted webpages as part of a DNS filtering service. Some secure DNS servers also offer enhanced privacy to protect user data, such as Private DNS servers, which delete all DNS query records after some time.

Since DNS was not intended with security in mind from the start, there are additional techniques to make the DNS process safer besides DNS filtering. For example, the DNSSEC ensures that DNS resolvers provide accurate information and are not compromised. In addition, DNS over TLS (DoT) and DNS over HTTPS (DoH) encrypt DNS queries and responses, making it difficult for attackers to track a user’s DNS requests.

Why should you filter DNS?

Due to its adaptability, DNS filtering provides customers with advanced customization options. You can select which content types are allowed and which should be blocked based on the requirements of your organization. In addition, you protect your users from harmful content by implementing DNS-based web blocking. In addition, DNS filtering provides additional benefits, such as: 

• Stops visitors from visiting dangerous or harmful websites.
• Includes simple category-based filtering, blacklisting and whitelisting.
• It prevents visitors from going to phishing websites.
• Stops the download of potentially illegal files.
• Make browsing safe and secure for network users, Wi-Fi users, and visitors.
• Restricts malware downloads for users

What types of DNS attacks can target me if I don’t have DNS filtering?

• DNS cache poisoning (DNS spoofing): The goal of this attack is to taint the recursive servers, specifically the cached replies. If they are successful, any following query will receive a poisoned response.
• DNS hijacking: This attack aims to send DNS messages to a different domain name server with completely bogus information to redirect users to dangerous web pages. Because it is sent to a different location, malware on the target client PC might enable all DNS requests to be routed to the attacker’s controllable DNS server.
• DNS tunneling: It drills into DNS messaging and passes malware using SSH, TCP, or HTTP. DNS tunneling entails encoding communications in DNS queries and responses. This DNS attack leaks sensitive information, in which case the constantly changing domain names make it very challenging to catch.

DNS filtering vs Web filtering

There are two different kinds of content filtering: DNS filtering and web filtering. DNS filtering restricts website access based on DNS queries. On the other hand, web filtering prevents access to specific websites based on their URL. As DNS filtering can prevent access to websites even before they are loaded, it is often more effective than web filtering.

In general, web filters are less precise than DNS filters. This is because DNS queries are frequently more accurate than URLs. For instance, a DNS query for “example.com” will always result in the same IP address. But, depending on your region, the example.com URL can change. Whether you are logged in, or not can also affect how it changes.

Web filtering typically takes longer than DNS filtering. This is because DNS queries often resolve more quickly than URLs. DNS filtering might also obstruct access to websites using secure connections (HTTPS).

Comparison DNS filtering with other security measures

DNS filtering is a vital security layer, but it’s important to understand how it compares with other measures:

• Firewalls: Firewalls control incoming and outgoing network traffic based on predefined security rules. While DNS filter blocks access to harmful domains, firewalls regulate data packets based on source, destination, and types of traffic, offering a different layer of security.
• Antivirus Software: Antivirus programs detect, prevent, and remove malware. DNS filter complements this by preventing access to malicious sites where malware can be downloaded, thus reducing the antivirus software’s load.
• Email Filtering: This specifically targets email threats like phishing and spam. DNS filtering adds an extra layer of security by blocking access to malicious links that might be missed by email filters.
• Endpoint Protection: Endpoint protection focuses on securing endpoints in a network. While this is crucial for detecting and responding to attacks, Domain Name System filtering prevents threats at the network level before they reach endpoints.

Can DNS filtering be bypassed?

While DNS filtering is a powerful way of safeguarding against online threats, it is not infallible. Skilled individuals can bypass DNS filters using various methods such as Virtual Private Networks (VPNs), proxy servers, or by changing the DNS settings on their devices. These methods allow users to avoid the restrictions set by DNS filtering by routing their internet traffic through different servers. To counteract this, it’s important for organizations to employ a comprehensive security strategy that includes regular updates and additional protective measures alongside DNS filtering, DDoS Protection, DNSSEC, Private DNS servers, etc. These approaches ensure a robust defence against evolving cyber threats, maintaining the integrity of network security.

Conclusion

DNS filtering is essential for organizations that want to keep their networks and users safe, whether working in a public Wi-Fi environment or within their corporate network. It provides granular customization options to tailor user access policies, block unwanted content, and enhance privacy. With the constant threat of DNS-based attacks on the rise, implementing a reliable DNS filtering service is the key to ensuring a secure connection for all users.

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What is a DNS flood attack?

A DNS flood attack is a type of Distributed Denial of Service (DDoS) attack. It targets the DNS server, which is crucial for translating domain names (like www.example.com) into IP addresses that computers use to communicate. The attack floods the DNS server with an overwhelming number of requests, causing legitimate traffic to be delayed or completely blocked, effectively taking the service offline.

How does a DNS flood attack work?

Imagine a small post office suddenly receiving millions of letters, most with incorrect return addresses. A DNS flood attack operates similarly. Attackers leverage a network of compromised devices, known as a botnet, to send a deluge of DNS requests to a target server. These requests are often disguised with fake IP addresses, adding confusion and preventing easy filtering. The server, inundated by this tsunami of requests, struggles to respond, leading to legitimate requests being ignored or delayed – effectively disrupting normal web services. 

Let’s break down the process into steps:

1. Volume of traffic: The attacker sends a massive amount of DNS requests to the target server, often using a network of compromised computers (botnets).
2. Spoofing IP addresses: These requests often have fake return addresses, making it hard for the server to distinguish between legitimate and illegitimate traffic.
3. Server overload: The DNS server becomes overwhelmed, trying to process each request, leading to slowed down services or a total shutdown.
4. Secondary effects: The attack can also impact other services that rely on the DNS server, creating a ripple effect of disruption.

Why is it dangerous?

The danger of DNS flood attack cannot be overstated. They are more than just an inconvenience; they pose a significant threat to online operations. Firstly, they can cause major disruptions to essential services, crippling websites and online platforms. This disruption can have a cascading effect, impacting not only the targeted site but also any service that relies on it. The financial implications are equally severe, especially for businesses that depend on online transactions or services. Beyond the immediate financial losses, these attacks can inflict long-term damage to a company’s reputation, shaking customer confidence and trust. Moreover, while the focus is on mitigating the attack, other security vulnerabilities might be overlooked, leaving the door open for further exploits.

How to recognize a DNS flood attack?

Identifying a DNS flood attack primarily involves monitoring for an abnormal surge in DNS traffic. This is where tools like ClouDNS Free DNS tool come into play. This innovative tool enables users to inspect DNS records for specific hosts and analyze the speed and volume of DNS queries. Users can conduct a thorough audit of their DNS traffic, a crucial step in early detection. The tool’s user-friendly interface and comprehensive functionality, including compatibility with major DNS resolvers like Cloudflare, make it an invaluable resource in a cybersecurity toolkit.

DNS flood attack mitigation

To defend against DNS flood attacks, consider the following strategies:

DNSSEC (Domain Name System Security Extensions):

DNSSEC adds an extra layer of security by verifying the authenticity of DNS responses. This helps ensure that the data hasn’t been altered, making it harder for attackers to exploit the DNS system.

DDoS Protection Service:

DDoS Protection services specialize in distinguishing and mitigating abnormal traffic patterns characteristic of DDoS attacks. They can redirect malicious traffic, keeping your DNS server operational.

DNS Monitoring:

Regularly monitoring DNS traffic for unusual patterns helps in early detection of potential attacks, allowing for swift action before significant disruption occurs.

Enabling DNS Caching:

DNS caching reduces the load on servers by storing responses locally. During an attack, cached data can still be served, maintaining service availability for some users.

Secondary DNS:

A Secondary DNS provides redundancy. If your primary server is overwhelmed, the secondary server can maintain service availability, minimizing downtime.

DoT (DNS over TLS) and DoH (DNS over HTTPS):

Implementing DoT and DoH encrypts DNS queries, enhancing security. They help differentiate legitimate traffic from malicious queries, as most attack traffic doesn’t use these secure channels.

Conclusion

In summary, effectively mitigating DNS flood attacks involves a blend of strategic defenses and proactive monitoring. By adopting a range of protective measures and staying vigilant, organizations can safeguard their online presence against these disruptive threats. Remember, a robust defense is essential in maintaining the integrity and reliability of your digital services in today’s interconnected world.

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