What is a DDoS attack?

DDoS attack stands for Distributed Denial-of-Service attack and represents a cyber-attack that aims to disrupt normal traffic and make the target (website, server, network) unavailable for regular users. There are few different types, but in general, a DDoS attack is an attempt to overwhelm the target (a computer, few connected computers or a whole DNS network) with high traffic from multiple sources.

The cybercriminals can generate this strong wave of traffic by:

• Using a network of pre-infected devices (computers, mobiles, IoT devices, etc.)  called a botnet
• Amplify attack that uses other servers to resend the traffic to a target after significantly increasing the size of the packets
• Occupy the existing connection and not allow new ones
• Exploit the vulnerabilities of a protocol, such as the UDP or another. 

There are many DDoS threats, this is why you want to a DDoS defense too. DDoS attack protection could keep your business safe and notify you of problems.

How does it work?

There are different types of DDoS attacks (volume-based attacks, protocol-based attacks, and application-layer attacks), but in general, they all have the same stages:

1. Pre-production of the attack. At this moment, the cybercriminals will create a network of botnets (infected devices) that later they will use for attacks. For example, hackers can bypass the security of IoT devices, or they can send phishing emails to users, and when the users open the emails, they can get infected with malicious code. 
2. Launching of the attack. Now it is time to use the botnet. Time for choosing a victim and sending the traffic towards the targeted server. There are different reasons for the attacks, but the goal is to saturate the target with traffic and take it out of service. 
3. The success of the attack. After a while, if the target does not have DDoS attack protection, or it is not strong enough, eventually it won’t be able to function correctly. There is a limit to how many active connections a server can have, even if it is very powerful. It will start to deny service and stop working. Normal users will not be able to use the server until the traffic drops again and the server can begin responding to normal queries. 
4. Final result. The bad actors could have achieved different goals, and now they get their reward. It could be money or just satisfaction with the success of the attack.

Signs of DDoS attacks 

DDoS attacks are extremely harmful and could lead to large reputational and financial losses. That is why it is crucial to be mindful and observe for any early signs of an appearing attack. There are specific characteristics of each DDoS attack type, but in general, what you can expect during an attack is: 

• Strange traffic, coming from one IP address or various but similar IP addresses (same range of addresses). 
• Traffic coming from devices with a similar profile (the type of devices, OS, etc.) and same patterns. 
• Out-of-ordinary traffic spikes like a huge spike, in the middle of the night without any sense or repeatable traffic, with a particular interval. 
• Traffic only to a single page, and no further exploration of your website.  

DDoS vs. DoS 

Let’s first briefly define a Denial of Service (DoS) attack. In this type of online attack, a source is maliciously infected in order to send big amounts of traffic to a target. The purpose is to saturate the system, to make it crash by exhausting its technical resources (CPU, RAM, etc.), or by exploiting a specific vulnerability and injecting a proper, harmful input. Then the service for users will be denied.

Now, let’s jump to the differences between DDoS vs. DoS attacks:

• Sources for attacking. In DoS attacks, the perpetrator only needs one Internet-connected device (source) to flood its victim with lots of forged requests or exploit a specific vulnerability within its software. DDoS attacks are executed from multiple sources, thousands, even millions of devices connected to the Internet.
• Way of execution. Generally, DoS weapons are apps like Low Orbit Ion Cannon or homemade codes. DDoS perpetrators use botnet armies, massive groups of malware-infected devices like PCs, routers, mobiles, Internet of Things (IoT) connected to the Internet. The traffic a DDoS attack can produce is heavy, much bigger than a DoS attack can.
• Damage scope. Both attacks can be very aggressive. But still, modern technology makes it easier to defend and even track the malicious source of a DoS attack, increasing the chances of identifying it and defeating it. It becomes a one-to-one fight (DoS). During a DDoS attack, you are fighting against multiple devices, possibly located in different countries or continents. You would have to track and stop all of them simultaneously. This is more like a war, and it definitely will demand so much more time and resources for the victim to defend and try stopping the attack. Thus, the damage scope of a DDoS is wider than the DoS one.

DDoS attacks Protection

There is a solution that can stop most of the DDoS attacks, even a strong attack involving heavy traffic, called DDoS Protection. It is an additional service to a regular managed DNS plan. 

To successfully mitigate a DDoS attack, you need to have the following 3 elements:

1. Active monitoring. You need a Monitoring solution system that checks for signs of attacks like increased traffic, suspicious traffic from particular IP addresses, and strange patterns of requests. 
2. Reactive service. One thing is to see the danger. Another is to take action. Good DDoS protection service must have auto triggers that will take action. This may include load balancing, traffic filtering, and an alarm system. 
3. Traffic load balancing. When we talk about heavy traffic, you need to direct the traffic to more servers. That way, you will balance the hit on one and disperse it to more. The more DNS servers your plan includes, the better possibility you have to resist the DDoS attack. 

You need to have an intelligent DDoS attack protection service that can distinguish between heavy traffic because of your excellent promotion or real danger. You don’t want to block your real users at any moment.

Discover Web monitoring from CloUDNS

What is the motivation of DDoS attackers?

Cybercriminals can have multiple reasons to use a DDoS attack, and the most common are:

• Extortion. The attacks can send waves of traffic towards the target and disturb the functionality of its services, causing technical problems, downtime, and miss of sales, demanding money for stopping the DDoS attack.
• DDoS-for-hire to attack the competition. On the Dark Web, people can hire hackers for DDoS attacks. Some people pay for such an attack to be directed towards their competitors. It is especially popular during important sales moments like Christmas, Black Friday, Cyber Monday, or Easter promotions. If the competitor is down, it won’t receive visitors on its site, and they will go to another place. The one who paid the attack hopes a part of these visitors directs to its site.
• Cyberwarfare. The governments of some countries use DDoS attacks to target the opposition’s news sites, their communication, or other crucial services. The goal is to control the narrative and not allow free speech in their country. These attacks could be especially strong because countries have a lot of money for sponsoring them.
• Gamers’ conflicts. You could be surprised, but the gaming industry has already reached almost 200 billion dollars in revenues per year, so the stakes are high. Rival gamers use DDoS attacks to bother their competitors and try to lower their scores. Sometimes, they use DDoS to stop a competition game they are losing and demand a re-match.
• Hacktivism. Hackers also have an opinion. They might have a problem with the government, with a particular organization or event. Modern activism has many new ways to protest and express a point that includes cyberattacks.

Types of DDoS attacks

Over time, cyber criminals managed to create multiple technical approaches for taking out their victims through DDoS. Each of the techniques falls into one of the three general types of DDoS attacks, which are the following: 

Volume-Based or Volumetric Attacks

These are the most classic type of DDoS attacks. They use different methods for generating massive volumes of traffic to overwhelm the capacity of the victim’s resources. As a result, servers are overwhelmed with requests, networks are overwhelmed with traffic, and databases are overwhelmed with calls. Additionally, they saturate bandwidth and produce large traffic, which results in it being impossible for legitimate user traffic to flow into the targeted website.

Protocol Attacks

Protocol attacks, also known as state-exhaustion attacks, abuse protocols to overwhelm a particular resource, most commonly a server but occasionally firewalls or load balancers. They are designed in a way that allows them to consume the processing capacity of network infrastructure resources. Their target is usually Layer 3 and Layer 4 protocol communications and, more precisely, their weaknesses. These attacks are often measured in packets per second.

Application-Layer Attacks

These DDoS attacks target weaknesses in applications in order to force the application itself to fail. In contrast to other attacks that mainly concentrate on disrupting infrastructure, these attacks are initiated on Layer 7 (the Application layer) by opening connections and starting processes and transaction requests that consume limited resources, such as disk space and available memory. Yet, it can even result in overloaded CPUs or exhausted memory, which impacts the server and other applications. Layer 7 attacks are well-known that are difficult to prevent since it can be challenging to distinguish malicious traffic from regular traffic. Application DDoS attacks are usually measured in requests per second.

In real-world cases, criminals can actually use a combination of these types of DDoS in order to increase the intensity of the attack.

Popular DDoS attacks used by hackers

Let’s talk a little bit more about the most popular types of DDoS attacks initiated by cybercriminals!

Smurf Attack

The Smurf attack is performed over the ping tool (ICMP echo request). The ping tool is used to check the reachability of connected devices.  When you send a ping request to the destination address, you should receive a confirmation. In this DDoS attack, the ping is sent to a device but from a masked IP. The return confirmation doesn’t go to the original source, but it is redirected to the target of the attack. All the infected devices will do the same, and they will send the traffic to the victim.

Teardrop Attack

A Teardrop attack works by sending modified, oversized data packets to the victim’s device to make them inaccessible. Frequently, perpetrators use a specific bug for destabilizing the fragmentation codes or the reassembly feature of the TCP/IP protocol. This opens the door for the teardrop attack to happen.
Reassembling the maliciously modified data packets won’t be possible. This will produce repeated attempts to complete the task. And the constant cycle of these repetitions will cause the overlapping of the packets. Finally, to increase the strain, big traffic loads will be sent to the target for a definitive crash.

Ping Of Death

The Ping Of Death (POD) attacks using a common and valid tool with malicious objectives – the Ping command. Altered or oversized data packets are sent to the target through the ping command.
Consider that a correct IPv4 data packet (IP header included) must be 65,535 bytes. This is the standard allowed by the Internet protocol (IP). Perpetrators violate it and make the target struggle while trying to reassemble altered packets repeatedly. Target’s resources like memory will be exhausted, causing different problems, crashing included.
POD became popular because attackers don’t need deep knowledge about its victim, only its IP address.

Slowloris

A highly dangerous attack executed a single computer vs. a server. A sophisticated technique that takes down a server without disrupting the rest of the network’s ports and services. Slowloris operates by sending many partial requests to the server. It keeps sending more and more HTTP headers continuously but without completing those requests. These forged requests keep many connections open to the server for a longer time than usual to overwhelm the maximum concurrent connection pool. As a result, the system will slow down, additional connections from legit users will be denied.

Zero-day DDoS attack

A Zero-day, also called a zero-minute attack, is one that takes advantage of new vulnerabilities. People are not yet aware of them. Usually, those vulnerabilities appear on new updates or patches, but they can also exist since the software is launched. The name of the attack refers to the fact it is happening before the vulnerability perpetrators used is publicly known.

This attack can have a positive purpose when software companies pay people in exchange for reporting vulnerabilities of new products before their official release. But it also points to the reality that attacks are far from disappearing.

Preparing a DDoS attack

To launch a DDoS attack, first, the criminals need to “recruit” enough connected devices that later will generate the traffic. To do so, they infect those machines with different malicious software (from emails, visiting unprotected sites and more) and create so-called botnets – hijacked devices ready to be used when it is time for the attack. There are even markets for botnets, where you can buy an attack on a website of your choice.

The Consequences of DDoS attack

Experiencing such a harmful threat is highly unpleasant and can have a huge negative impact. Some of the possible outcomes of a successful attack include:

• Operational Disruption: One of the immediate consequences of a successful DDoS attack is the disruption of normal operations. Websites become sluggish or entirely inaccessible, leading to frustrated users, decreased productivity, and financial losses. E-commerce platforms, financial institutions, and online services are especially vulnerable, as downtime translates directly into revenue loss and damage to customer trust.
• Financial Loss: DDoS attacks can cause severe financial harm. Businesses may face not only the direct costs of mitigating the attack and restoring services but also indirect costs associated with reputational damage and lost customers. The financial damage can lead to legal consequences, especially if sensitive client information is compromised during the attack.
• Reputational Damage: Trust is a delicate matter in the digital space, and a DDoS attack can destroy it instantly. When customers cannot access services or experience disruptions, they may lose confidence in the affected organization and its ability to protect their interests. Rebuilding a reputation can be a long and difficult process.

How long does a DDoS attack last?

The duration of a DDoS attack can vary significantly based on the resources available to the attackers and the defensive measures of the target. DDoS attacks can last from a few minutes to several weeks. On average, however, most DDoS attacks last for around 24 hours, though some intense attacks can go on for days or even weeks.

Short-duration attacks can be a part of a coordinated strategy where attackers test a target’s vulnerabilities with brief bursts, estimating the response and preparedness of the target’s systems. These “hit-and-run” style attacks can cause considerable disruption in a short time, particularly if they target time-sensitive operations like financial transactions or sales events.

Prolonged DDoS attacks typically aim to exhaust the target’s resources or force them to pay a ransom in exchange for stopping the attack. Long-term attacks can be devastating as they may prevent an organization from functioning entirely, leading to major operational and financial issues.

Preparedness and robust DDoS protection are essential to mitigate the effects of both short and prolonged attacks.

Which industries are being targeted and why?

Certain industries are more frequently targeted by DDoS attacks due to their high online activity, competitive nature, and dependence on continuous uptime. Here are some of the industries most affected and why they are popular targets:

• Financial Services and Banking: Financial institutions are high-value targets due to their critical role in managing and securing funds and customer data. Attackers may aim to disrupt operations, damage reputation, or extort these institutions for ransom. A successful attack on a bank can lead to significant financial loss, operational chaos, and damage to customer trust.
• E-commerce and Retail: Online retail is another major target, especially during peak shopping seasons like Black Friday and holidays. Attacks during these times can severely impact sales revenue, as website downtime directly translates to lost customers and sales.
• Government and Public Sector: Government websites, especially those related to public communication, law enforcement, and emergency services, are frequent targets. These attacks may be politically motivated, intending to disrupt public access to information. Governments are also targeted to disrupt official communication channels.
• Gaming and Entertainment: The gaming industry is particularly vulnerable, as users expect real-time access and responsiveness. Gamers often participate in competitive or time-sensitive events where even short downtimes can lead to significant frustration and financial loss for companies. DDoS attacks are frequently employed to disrupt gaming servers.
• Media and News Websites: News outlets and media websites are also prime targets. Hacktivists may use DDoS attacks to silence certain news outlets or delay the publication of specific content. Attacks on these sites can reduce public access to information, potentially affecting the narrative on important topics.

How to prevent a DDoS attack and stay safe?

The cyber-criminals can make a vast network of botnets, but it doesn’t mean you can’t be protected. ClouDNS provides you two options to stay away from DDoS troubles.

You can choose and subscribe for a DDoS protected DNS.

All plans provide unlimited Layer 3-7 DDoS Protection. Whichever you pick from them, you will be able to use 4 DDoS protected DNS servers, 50+ Anycast locations and unlimited DNS queries. For big companies, we recommend our DDoS Protection L subscription with 400 DNS zones that you can manage.

DDoS Protected Plans

Or you can use a Secondary DNS as a backup DNS, so you always have a backup copy of your DNS records.

It adds resilience, reduce the outage periods by answering requests even if the Master is down.

Conclusion

The more extensive your DNS network is, the better. The massive traffic from the attackers can be distributed between your servers in the different locations, and it will ease the load. Don’t forget that modern DDoS attacks target different communication layers, so you will need intelligent DDoS protection to respond fast and accurately. 

To be safe, always choose quality DNS service provider like ClouDNS.

The post DDoS attacks and how to protect ourselves appeared first on ClouDNS Blog.

DNS outage (DNS downtime) – what does it mean? 

The DNS outage (a.k.a. DNS downtime or DNS failure) is a period of time when the domain name can’t be resolved to its IP address. The clients will send a DNS query for a domain name, but the DNS recursive will either answer with the old IP address from its cache, which will not respond, or it will try to query the DNS authoritative name server of the domain name won’t get an answer. 

What causes DNS outages? 

DDoS attacks

DDoS or a denial of service attack, is a type of cyber-attack that involves multiple devices that work together, targeting a victim’s computer, with a large amount of traffic intending to make it unable to answer any more queries. To prevent any problems that a DDoS attack can cause, you will need a load balancing that can share the traffic between your servers, even if it is very strong. And also, you will need DDoS-protected servers. 

Maintainance of the authoritative name server

If you are using only one authoritative name server, whatever happens to it, can affect your DNS. If it needs updates and reboot, the time that it takes, the server won’t be able to respond to DNS queries. Updates and maintenance are needed, so you better have a Secondary DNS that can answer the queries meanwhile. 

A problem in the data center, where the authoritative name server is

The cloud equipment does not magically hover over the Earth. Instead, it resides in multiple data centers. These places can have problems like long-lasting electricity outages, natural disasters affecting the area, fire, or other problems. If you are using a cloud service, these issues are out of your hands, but you can use multiple servers in multiple data centers. If one is down, still, there will be more to answer the queries. 

Bad configuration

Errors in DNS configuration can cause DNS downtime. It can be a human mistake, like badly addressing caused by misspelling the IP address or domain name, script error, wrong firewall configuration, etc. 

If it is a misspelled problem, you can try to query the domain name and the IP address to see which does respond and which does not. 

If it is the firewall, you can check the ports if they were allowed. 

DNS propagation delay

When you add or remove DNS records (like A or AAAA records), the changes are not always instant. You are editing the zone file inside the Primary DNS server, and you can propagate to your Secondary DNS servers, but there are many DNS recursive servers that you don’t control. They can keep your old IP address and provide it to clients, even after you published a new one. 

What you can do about the DNS propagation is to push the zone transfer to your Secondary servers and to keep lower TTL values for your DNS records. 

It is not technically a DNS outage because it will affect only those with the older cached IP address of the domain name, but it was worth mentioning it.

How to avoid DNS downtime (outage)

The best way to avoid DNS outages is to have a robust DNS network that provides redundancy and can withstand strong traffic. The more servers you have, the better you are going to be prepared. Additional features might also facilitate the DNS administration and automate the process of handling problems. 

Use Secondary DNS services

A secondary DNS service provides you with the opportunity to use multiple Secondary DNS servers, which can be set as Secondary authoritative nameservers. They will have a copy of the zone file with the DNS records. They can answer queries for your domain, just like the Primary one. The big advantage is that they will keep answering even if the Primary is experience downtime. Having Secondary DNS is your DNS backup solution. 

You can learn more about it in this article, “What is backup DNS?”, and you can try our Secondary DNS plans with a 30-day free trial. 

Use DNS load balancing

DNS load balancing is also another nifty way to lower the chance of DNS outages. It is a mechanism for administrating the DNS traffic between the DNS server, based on criteria like the number of active connections, specific algorithm, time of connection, etc. 

It will reduce the stress on a particular DNS server and spread it between the network. 

It can help in case of a DDoS attack but also in a natural spike in traffic caused by increased clients’ queries. It can help you during a promotional period when you are experiencing higher traffic.

Be prepared with DNS Failover

DNS Failover is a trigger that will activate in case of a nameserver’s failure. It can automatically redirect the traffic without any human interaction, based on the information it gets from DNS monitors like ICMP ping, UDP requests, HTTP checks, etc. It is an easy way to keep your clients’ happy and provide DNS resolution, even if some of your DNS servers are experiencing some problems. We offer DNS Failover service with all of our paid plans.

Also, we recommend you to check our Brand new Monitoring service!

How to diagnose DNS outages?

When facing a DNS outage, quick diagnosis is essential to restore functionality. Follow these steps to pinpoint the problem:

• Ping the Domain

Use ping to check if the domain resolves and the server responds.

ping example.com

If it doesn’t resolve, it’s likely a DNS issue.

• Test DNS Resolution with nslookup

Verify if DNS is working by querying your DNS server with nslookup.

nslookup example.com

If it returns an IP address, DNS is working for that domain. But if it fails, the DNS server may be down or misconfigured.

• Run dig for detailed queries

Use dig for detailed DNS resolution data, including specific DNS record types.

dig example.com

Add +trace to follow the query path through name servers and find where it fails.

• Test with Alternate DNS Servers

Query public DNS servers (like Google’s 8.8.8.8) to rule out provider-specific issues.

nslookup example.com 8.8.8.8

If the domain resolves with a different DNS server, it suggests the problem is with your original DNS provider.

• Check DNS Propagation Delays

If you’ve recently made DNS changes (such as updating A or MX records), delays in DNS propagation could be the culprit. Use online tools like ClouDNS Free DNS tool to check whether your DNS records have propagated across global DNS servers.

• Check for DDoS attacks or high traffic loads

DNS outages can be caused by Distributed Denial of Service (DDoS) attacks or heavy traffic loads. Tools like TCPdump can help capture and analyze DNS traffic to detect abnormal patterns, such as a flood of queries or unusual IP activity.

Example:

sudo tcpdump -i eth0 port 53

This command captures DNS traffic, allowing you to inspect for signs of an attack. For real-time detection, combine TCPdump with network monitoring tools and DDoS mitigation services.

Troubleshooting 

What can you do when your domain is not reachable? 

As DNS administrator of the domain name, you can: 

• Suppose you have recently finished a DNS delegation. You might need to way up to 24 hours, so the changes are well propagated. 
• Check if you have paid for your domain name. If you have forgotten to pay your domain name, it won’t answer queries anymore when it expires. Set reminders for domain renovation and don’t miss the time. 
• Use the ping command to ping the DNS server from different locations to see if it is responding to any DNS requests. It is possible that you haven’t set up your nameservers correctly, and they are working but not answering queries for the domain name. 
• Try to reach the DNS server by using its IP address. If you can reach it, there might be a badly configured A or AAAA record that does not link well the domain name and its IP address. 
• Check your DNS monitor and see how the traffic is going. If you can’t see the monitor’s log, check if there were any unusual activities before the server stopped working. For example, it could have been a DDoS attack. If it is still happening, you can redirect the traffic and stop it. 

As a client who can’t reach a site: 

• You can have problems with the DNS cache of your device. You can flush the DNS of your device and your browser. This action will remove the previous DNS records that you have, and your device will search again for the A or AAAA record of the site you want to visit. If you had an older IP address, this could fix it. 
• Maybe your router is the problem. The router has a recursive DNS server that may need to be restarted. Pull its plug, then wait around a minute and connect it again. It should reboot and start working well again. 

Monitor your DNS server

Monitor your DNS for any strange pattern in traffic. There are different automatic monitors that you can set to see the traffic behavior. If something strange happens, you can see in almost real-time any changes and use the information to take action. 

You can monitor the DNS from different locations. That way, you can see if the problem is very local, is it regional, continental, or global. It will be easy to spot the problem.
DNS monitoring works best in combination with DNS Failover. You can set the monitor with the parameters that you prefer, and it will notify you and show you the data. But when you also have DNS Failover, you can connect this data and trigger automatic even in case of a down server. It can deactivate DNS records and replace them with working. It can also react in case the server gets up and add it to the list again. 

ClouDNS offers DNS Failover service for all of its paid customers. You can set it up and activate it for your domain fast and easily.

What are the consequences of a DNS outage?

If a DNS outage occurs, it could have a negative impact on your entire organization and community of customers. When DNS (Domain Name System) is down, websites, applications, and online services related to the domain name, such as emails, won’t function correctly. Unfortunately, that has the potential to damage operations, revenue, and brand reputation. In addition, you should act fast and quickly get it up and running again to regain all the temporarily lost functionality.

Yet, let’s assume the functionality of the DNS operations was seriously interrupted for a prolonged period of time. In that case, a DNS outage can potentially cause devastating consequences to the companies with an online presence. Here are some of the most common effects during this time: 

• Miss potential visitors
• Lose potential sales
• Have issues with services like email, FTP, VoIP, etc.
• Productivity losses
• Damage to reputation
• Impact on customers and strategic partners
• Diminished competitive advantage

It is crucial to implement all precautionary measures to avoid DNS outage’s negative influence on your business.

The biggest DNS outages in the history

• 2016 Dyn DNS Interruption: A significant disturbance shook the internet when Dyn, a leading DNS service provider, fell victim to an attack. Websites with heavy traffic, such as Twitter, Spotify, and Reddit, experienced outages. This event underscored the vulnerabilities tied to unsecured IoT devices.
• 2019 Cloudflare Outage: A misconfigured web application firewall rule caused a major disruption in Cloudflare’s services, impacting millions of websites.
• 2019 Google Cloud Outage: In June 2019, Google Cloud Platform experienced a significant outage that affected multiple services, including Gmail, YouTube, and Google Cloud Storage. A configuration change intended for a small number of servers in a single region was mistakenly applied to a larger number of servers across several neighboring regions.
• 2020 AWS Outage: In November 2020, Amazon Web Services (AWS) faced a significant outage that affected several services reliant on AWS’s infrastructure. This incident disrupted many online services and platforms, highlighting the vulnerabilities in centralized cloud infrastructures.
• 2021 Fastly Global Outage: In June 2021, a major global internet outage occurred, affecting numerous high-traffic websites including Reddit, Twitch, and even the UK government’s official website. This was traced back to a software bug in the Fastly CDN network, a critical infrastructure provider for many internet services.
• 2022 Microsoft Azure DNS Outage: In mid-2022, Microsoft’s cloud service, Azure, experienced a DNS outage. It impacted a wide range of services, from basic operations in Azure to third-party applications relying on Azure’s infrastructure. The outage underscored the need for robust failover systems and redundancy in cloud services.

Conclusion

A huge DDoS attack can lead to a DNS outage even if you have excellent infrastructure. But applying all the measurements can lower the time and the frequency of the DNS outages. Be prepared and intelligently manage your DNS traffic to be able to provide excellent service for your clients. Keep your business up!

The post What is a DNS outage (DNS downtime), and how to avoid it? appeared first on ClouDNS Blog.

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.

Understanding DNS

Before delving further into DNS plan types, let’s familiarize ourselves with what DNS really is.Each time you enter a web address into your browser, a DNS server translates that address into an IP address, guiding your request to the right web server. Simply put, the DNS is the phone book of the internet – converting human-readable domain names into machine-readable IP addresses.

Free DNS

Different companies offer such a Free DNS plan like us from ClouDNS. With this plan, you can manage your DNS. It has many of the features of a professional DNS plan. You can use up to 4 DNS servers and 1 DNS zone. You will have one mail forward. This plan is popular among people who need Dynamic DNS for their connected devices like CCTV cameras and other security measurements. It is used for personal blogs or parked domains.

Using this plan, the user can use all kinds of DNS records, including A, AAAA, MX, TXT and more. Something that is rarely found in such Free DNS plans is that we provide unlimited DNS queries. This can be a big plus.

It is a good plan for starters, who wants to learn using DNS. People who want to experiment and get how does the DNS work. It can be useful for small blog sites that still don’t get too much traffic. This kind of plans can’t offer the uptime of the Premium DNS plans so users of it, can experience occasional downtime and they are more vulnerable to DNS attacks.

Look how to add Free Zone in ClouDNS!

Premium DNS

Premium DNS plans have more of everything. They can use far more DNS servers and DNS zones. They can manage the traffic better. By using such a plan, you can see improvement in the loading speed, the security, better uptime and even better SEO.

DNS and SEO: How does DNS service affect SEO?

This kind of plans are for every website, that is more than just a personal blog with few monthly visitors. Every company that can’t afford to have downtime should choose a professional plan.

Premium DNS vs. Free DNS

When it comes to managing online data flow and protection, choosing the right type of Domain Name System (DNS) is crucial. Our comparison between Premium DNS and Free DNS will provide an understanding of the features, capabilities, and benefits that each service brings to your online activities.

• Better uptime – Our Premium DNS plans offer 60+ Anycast locations, up to 8 DNS name servers. You can also enjoy DDoS protection for maximum, SLA guaranteed, uptime. In case of a downtime, for each minute, we will extend your account with 10!

• More advanced features – Many more DNS zones and DNS records, unlimited queries, and many more mail forwards, DNSSEC, Reverse DNS zones, and more. Don’t forget DNS Failover and Monitoring checks.

• More DNS servers – Up to 8, depending on your plan. And up to 4 DDoS protected ones. They are strategically located around the world.

• Anycast DNS for better load balancing – Anycast is far superior technology in comparison with the older Unicast protocol. It manages queries a lot more efficiently. It provides the best route for each query to reduce latency.

• DDoS protection for extra security – DDoS attacks have been widespread for a while. They can completely cripple your network. ClouDNS offers 4 DDoS protected servers that can resist even heavy traffic.

• More DNS Zones – The free DNS plan that we offer has just 1 DNS zone that you can manage. The premium plans offer up to 400!

• Secondary DNS zones – You can use our Secondary DNS zones if you already have the master elsewhere. It is easy to set up, and it doesn’t take a long time. With Secondary DNS zones, you can improve the redundancy.

• More Mail Forwards – The free DNS plan has 1, but the premium plans have up to 1000.

• Real-time statistics – While the free plan provides statistics, it only on a daily, monthly, or yearly basis. If you want advanced real-time statistics that updates hourly check the premium plans.

How to Transition from a Free DNS Plan to Premium DNS with ClouDNS

Transitioning from a Free DNS plan to a Premium DNS plan on ClouDNS is a straightforward process that can significantly enhance your website’s performance, security, and reliability. Here’s how you can easily make the switch:

Step 1: Log into Your ClouDNS Account – Start by logging into your ClouDNS account. Use your existing credentials to access the dashboard where you manage your DNS settings.

Step 2: Locate the Upgrade Option – Once you’re logged in, look for the “Free” icon situated next to your email account at the top of the dashboard. This icon indicates your current Free DNS plan and provides a quick access point to upgrade.

Step 3: View Available DNS Hosting Plans – Clicking on the “Free” icon will bring up a list of all the DNS hosting plans that ClouDNS offers. This includes various Premium DNS plans tailored to different needs. Here, you can review the features and benefits of each plan to determine which one suits your requirements.

Step 4: Choose Your Plan Duration – After selecting the Premium DNS plan that fits your needs, you’ll be prompted to choose the duration of your subscription. ClouDNS offers multiple options, including 6 months, 1 year, or 2 years. Pick the period that best aligns with your budget and long-term plans.

Step 5: Complete the Purchase – Once you’ve selected your plan and duration, click on “Buy Now” to proceed to the checkout. You will need to fill out the required information to complete the payment process. ClouDNS supports various payment methods, making it convenient to finalize your purchase.

After completing the payment, your account will be upgraded to the Premium DNS plan. You can now take advantage of enhanced features such as better uptime, increased security, and improved DNS management tools.

Contextualizing your DNS needs: Factors to consider

Opting for either a free or Premium DNS service is not a decision to be taken lightly. While it’s tempting to choose the most economical option, it’s wise to weigh certain considerations to make an informed choice for your website’s long-term success:

1. Size and nature of your needs: Personal blogs and small websites usually don’t require the robust features of a Premium DNS, making a free DNS a reasonable choice. However, for larger websites or e-commerce platforms where downtimes mean lost revenue, Premium DNS services become indispensable for their reliability and stability.
2. Security concerns: Websites dealing with sensitive user data, especially eCommerce stores, need to prioritize their security features like DNSSEC, which often come with Premium DNS. 
3. Budget: Of course, budget plays a crucial role in your decision. Evaluate how much you are willing to invest in DNS services and if it aligns with your website’s requirements.
4. Traffic volume: If your website witnesses a significant volume of traffic, a Premium DNS with load balancing and faster routing can dramatically improve the user experience. 
5. Scalability: If you foresee quick expansion and growth for your website, investing in a Premium DNS service could provide the scalability you will eventually require.

Why does your choice of DNS matter?

Your choice of DNS acts as the vehicle driving the smooth operation of your website. It’s not just about translating a domain name to an IP address; it’s about ensuring your website can efficiently connect with users around the world.

• Speed: The performance speed of your DNS can significantly affect your website’s loading speed. In an era where waiting an extra second can lead to visitors abandoning your site, a faster DNS lookup can make a considerable difference.
• Uptime: Imagine owning a physical store but randomly closing several times a day – definitely not good for business, right? That’s essentially what website downtime is. A reliable DNS server ensures maximum uptime for your website, leading to consistent user experience and potentially higher revenue.
• Security: An insecure DNS can expose your website to cyber-attacks, leading not only to potential revenue loss through downtime but also damage to your brand reputation. A secure DNS can act as your frontline defense against cyber threats.

Conclusion

There are plenty of reasons to choose a Premium DNS over a Free DNS plan. Think about your needs, how much traffic are you expecting and how important is the uptime for your business. If you are not sure, you can start with a Free DNS or a cheap plan and slowly upgrade with the time. But if you know your business needs our sales team is here to meet your requirements. Just fill the form and our Sales representative will contact you as soon as possible.

The post Can we use free DNS? Free DNS vs. Premium appeared first on ClouDNS Blog.

DNS explanation

DNS or Domain Name System is the backbone of the internet. It connects all the users to the content they need. That means it is a directory service which converts human-readable domain names into numerical IP addresses. It is a constant exchange of information, but sometimes the DNS fails and this causes downtime. A blackout period that can be evaded by using a Backup DNS.

Backup DNS

Backup DNS, also known as Secondary DNS or alternative DNS is a system of one or more DNS servers, who have a copy of the zone data (DNS records) of the Master (Primary) DNS server. It adds resilience, reducing the outage periods by answering requests even if the Master is down.

Backup DNS services provide an additional measure of insurance against service outages. They allow a website to remain up and running even if the primary DNS fails, often by serving DNS requests from a different location. Additionally, backups may use the same protocols as primary servers, or be hosted in distributed cloud networks, which increases reliability and performance. 

How does it work?

Backup DNS works through a few simple steps. Here are they:

1. First, when a user requests a website or application, the DNS query is sent to the primary DNS server. 
2. The primary DNS server then resolves the domain name to the corresponding IP address. But if the master DNS server is down, the request is rerouted to the backup DNS server. 
3. Then, the backup server resolves the domain name and returns the IP address to the requesting device, allowing access to the website or application.

Benefits of Backup DNS

Backup DNS is an essential part of any website or application infrastructure. The primary benefit of having it is improved website or application availability in the event of any primary DNS service failure. Your website or application will remain up and running even if the primary DNS fails, by redirecting users to a different DNS server. 

With a robust Backup DNS service, businesses are better protected from malicious attacks such as Distributed Denial of Service (DDoS) attacks. In addition, for even better safety from these types of cyber threats, there are DDoS Protected DNS services that add another layer of protection.

Backup DNS services can also provide faster DNS lookup times, improved representation of your website or application by serving identical content around the globe, and seamless switching in case of server outages. 

Another benefit lies in its scalability. It is designed to scale with any increase in traffic, both in terms of the number of queries handled and the size of the DNS database. As your website or application grows, Backup DNS can help ensure that you don’t lose any traffic simply due to lack of capacity. Additionally, this services often come with built-in features such as failover capabilities, Anycast DNS, and more, which can all improve the overall performance and reliability of your website or application.

What is the worst that can happen? Dyn DNS attack of 2016

Just ask the Dyn DNS users who were victims of the massive DDoS attack of 2016. Many well-known websites and services were affected: Airbnb, Amazon, Twitter, BBC, CNN, Etsy, Github, PayPal, Spotify, and more. Their users were left without service for quite some time. The attackers created a massive amount of traffic that caused the victim’s system to get stuck and eventually crashed. They did that by using an enormous amount of botnets IoT devices (internet of things). There are plenty of connected devices with low protection that can be easily hijacked. The number of such IoT devices is rapidly growing, but their security level is not improving. This means we will have plenty of similar DDoS attacks in the future.

Who needs Backup DNS?

Backup DNS is beneficial for any organization whose website or application is critical to their success, as it adds an extra layer of protection and reliability. 

It is particularly important for businesses that serve large amounts of online traffic, such as online retail, media, etc. This is because having a reliable Backup DNS prevents disruption of service and lost revenue. 

Additionally, businesses that are subject to malicious attacks, such as governments. banks, healthcare institutions, also benefit from Backup DNS services, as these services can help prevent attackers from overwhelming their primary DNS server.

Additionally, small businesses that are just starting out and may not have the budget of large companies also benefit from this backup service. Why? Because this service is at an affordable price and ClouDNS offers a 30 day free trial for no cost testing. Check out our Secondary DNS service! 

Ultimately, Backup DNS is an invaluable tool for organizations of any size.

Conclusion

If you have more DNS servers, working together on a grid, the traffic that comes from such a DDoS attack will distribute between them. Some of your servers may go down for a while, even your master DNS can go down, but thanks to the DNS backup, the rest will continue, and your clients won’t be left without a service.

The post What is Backup DNS? appeared first on ClouDNS Blog.

DNS zone is a delegated partition of the Domain namespace, container of DNS settings and DNS records inside a DNS zone file. The DNS records point domain names to IP addresses, show information about services, serve for verification and authentication purposes and more. 

The DNS namespace can have single or multiple DNS zones, each managed by a particular DNS host/service. It has a hierarchy structure where the top is the root level, followed by the top-level domain, domain, subdomain, etc. This division helps for administrative purposes. It decentralizes the DNS, making it possible to be managed on different levels, and also reduces the tasks of nameservers by dividing their responsibilities. It is like an enormous pie. Each piece of it allows better separation of the administrative load and helps with redundancy.

There are three types of DNS zones – Primary (Master) DNS zone for control, Secondary (Slave) DNS zone for redundancy and better performance and Reverse DNS zone for network troubleshooting and for email servers IP to validation.
 
The first contains all the original DNS records, and the second gets them from the Primary DNS zone. The process is called DNS zone transfer. The Primary DNS server could push it, or the secondary can get the changes when its cache expires. 

Don’t directly associate a DNS zone with a specific domain. A Domain Name System zone may contain single or multiple host names for the same domain; the important thing is that it is used for controlling a fraction of the namespace. DNS zones can be on the same servers too.

We also recommend that you read “What is Authoritative DNS server?“

Different types of DNS zones

There are different types of DNS zones, but in this article, we will set our eyes on just two:

• Primary (Master) DNS zone – holder of the original zone file (all the DNS records for the zone). You can manage a host through this zone.
• Secondary (Slave) DNS zone – holds a copy of the Domain Name System file. You can use them for better performance, for hiding your Primary, for backup and redundancy.
• Reverse DNS zone (rDNS) – Responsible for mapping IP addresses back to their associated domain names. This is the opposite of what a typical (forward lookup) DNS query does.

Primary DNS zone

Primary (Master) zones contain a read/write copy of the zone data. There could be only one Master zone on one DNS server at a time. All the DNS records added manually or automatically, are written in this Primary zone of the DNS server.
The data is stored in a standard text file – .txt. The advantage is that it is easy to back it up and to recover in case of problems.
Something essential is that to be able to make changes to the Domain Name System zone, the Primary zone must be available. If the server with your Primary DNS is down, you won’t be able to make any changes.
If you want to have redundancy, you must have the zone data accessible on multiple servers.

If you want to learn how to create a Primary zone in ClouDNS, check the following step-by-step tutorial:

• Click on the sign-in button and enter your email address and your password. Once you have logged in, you will see your Dashboard. From the list, you will notice that you do not have any registered DNS zones. 
• Click on the “Add new” button. In the pop-up window, click on “Master zone”. You can create your Domain Name System zone with the NS records you want. However, we recommend you to use the suggested ones.

If you want to check your domain’s NS records, we recommend you take a look at the second command from our article: 10 Most used Dig commands

• In the text field, enter your domain name without HTTP, HTTPS, or WWW. Example: yourdomain.com. Once you do it, click on the “CREATE” button.

You have successfully created your Primary (Master) zone. From the top menu, you will be able to manage your Master DNS zone with all of the available options. Here you will see all the DNS records you can create and use for your needs. From the list, you can see your hostname, the type of the record, where they are pointed to, and what the TTL is.

You can also check our wiki page about Master DNS zone.

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Secondary DNS zone

The Secondary DNS zone is a read-only copy of the zone data. Most of the times Secondary (Slave)  zones are copies of Master zones. They can also be copies of other Slave zones or Active Directory Zones.
If you try to change a DNS record on a Secondary zone, it can redirect you to another zone with read/write access. By itself, it can’t change it.
One of the primary purposes of a Slave zone is to serve as a backup. When the Primary zone is down, it can still answer requests for the zone from its copy.

Check the following step-by-step tutorial to learn how to create a Secondary (Slave) Zone in ClouDNS.

1. Click on the sign-in button and enter your email address and your password.
2. Once you have logged in, you will see your Dashboard. From the list, you will notice that you do not have any registered DNS. 
3. Click on the “Add new” button and then click on “Slave/Backup zone” 
4. In the first field, enter your domain name without HTTP, HTTPS, or WWW. Example: yourdomain.com. In the second field, on the right, add the IP address of your Master Server. Once you do it, click on the “Add Slave” button.

You have successfully created your Secondary (Slave) zone. From the top menu, you will see the available options for your Slave Zone. Here is also the IP address of your Primary Server. 

If you want to use Secondary DNS zones, you can also review our Secondary DNS page, and decide which of our premium plans is right for you.

Now you know what a DNS zone is and the difference between these two types – Primary DNS zone and Secondary DNS zone. For any additional questions about your DNS infrastructure, you can contact our customer support.

Reverse DNS zone

A reverse DNS (rDNS) zone is a DNS zone established for the purpose of resolving IP addresses into domain names. While a standard (forward) DNS query resolves a domain name into an IP address, an rDNS or reverse DNS query does the opposite, mapping an IP address back to its associated domain name.

The Reverse DNS zone encompasses two types: Master and Slave. The Slave Reverse DNS zone acts as a safeguard, maintaining a read-only copy of the reverse DNS records while remaining in sync with the Master zone to distribute load efficiently. In contrast, the Master Reverse DNS zone is the authoritative source that houses the original mappings of IP addresses to domain names. All modifications and updates to these records are made in the Master zone. For guidance on setting up Master Reverse DNS zones, refer to the following instructions.

The utility of rDNS zones can be seen in several areas:

• Network troubleshooting: rDNS is useful for diagnosing network routing problems and pinning down the source of network attacks. By using reverse DNS lookup, network administrators can identify the hostnames associated with IP addresses appearing in log files.
• Email Verification: The SMTP protocol used for email has a step where the recipient’s mail server checks the sender’s IP address in a reverse DNS lookup. This can be used as a simple way to verify the legitimacy of the email sender and helps in spam prevention.
• For Certain Internet Services: Some Internet services, such as FTP servers, often use reverse DNS lookups as part of their control strategies.

Suggested article: FTP vs HTTP: Understanding the Key Differences

In DNS, each octet (unit) of the IP address is reversed and placed in the in-addr.arpa (for IPv4) or ip6.arpa (for IPv6) domain. For example, the IP address 192.0.2.0 is represented in a reverse DNS zone as 0.2.0.192.in-addr.arpa. The PTR (pointer) record is then used to map this to a domain.

DNS Zone VS. Domain

In the domain namespace, the biggest difference between the domains and zones is that domains provide logical structure, and the zones provide an administrative structure. 

A domain is a subtree of the domain namespace. It shares its name with that of the top-most node, like yoursite.eu (eu domain). It could be divided into various zones that can be controlled separately.

A zone is a partition of the domain namespace that requires a Primary nameserver and can be managed separately. A zone can coincide with the domain and covers all of its subdomains, or it could be just a partition of the domain. You could have separate zones for mail.yoursite.com and ftp.yoursite.com for your domain yoursite.com.

DNS Zone Delegation

DNS zone delegation is the process of assigning authority over a specific portion of a domain’s namespace to a different DNS server. This is typically done by the owner of the primary domain when they want to delegate control over a subdomain to another party or server. The delegation is accomplished by adding NS (Name Server) records to the parent zone, pointing to the DNS servers that will manage the delegated subzone. This allows the parent zone to direct queries for the subdomain to the appropriate authoritative DNS servers, ensuring efficient and accurate resolution of DNS queries within the delegated zone.

For example, a large organization might manage a primary domain like example.com and have various subdomains such as hr.example.com, blog.example.com, and dev.example.com. By delegating these subdomains to different DNS servers, the organization can optimize its DNS management, ensuring faster query resolution and greater overall stability. 

Conclusion

In conclusion, DNS zones are the building blocks of the Domain Name System, enabling efficient management of DNS records and administrative responsibilities. They play a vital role in ensuring the reliability and accessibility of online services by facilitating proper domain-to-IP address mappings.

Premium Secondary DNS hosting - Try for free

The post What is a DNS zone? Primary and Secondary DNS zone and how to create it appeared first on ClouDNS Blog.

What is a flood attack?

A flood attack, often a form of Distributed Denial of Service (DDoS) attack, aims to overwhelm a system with superfluous requests, thus preventing legitimate requests from being fulfilled. The primary objective is to make the target service unavailable, either by consuming all its resources or crashing it altogether. Flood attacks exploit the limitations of a network’s bandwidth, memory, and processing power. By sending an excessive number of requests, they can exhaust these resources rapidly, causing severe disruptions. Attackers often use botnets, a network of compromised devices, to generate the enormous volume of traffic required for such attacks, making it harder to trace and block the sources.

How does it work?

A flood attack works by sending a massive volume of traffic to a targeted server, service, or network. This traffic often appears to be from legitimate users, which makes it challenging to distinguish and filter out. The target system gets overwhelmed by this surge in requests, which eventually leads to its degradation or shutdown. Flood attacks can be executed through various protocols and methods, such as TCP, UDP, ICMP, and HTTP, each exploiting different aspects of the network’s communication process. Advanced flood attacks may use randomization techniques to avoid detection and mitigation efforts, making them more sophisticated and harder to counter.

Why is flood attack dangerous?

• Disruption of service: The most immediate impact is the service disruption. Websites may become unavailable, networks may slow down, and businesses may experience downtime.
• Financial impacts: With downtime comes lost revenue. Especially for businesses that rely heavily on online services, a few minutes of inaccessibility can translate to significant financial losses.
• Damage to reputation: Continuous attacks can tarnish a company’s reputation, causing loss of customer trust and loyalty.
• Resource consumption: An immense amount of resources, both human and technological, need to be diverted to handle the aftermath of such attacks.
• Diversion: Sometimes, attackers use flood attacks as a smokescreen, diverting attention from a more covert breach or intrusion.

How to mitigate it?

• Monitoring: Continuous monitoring of network traffic can help in early detection of unusual traffic spikes, which may indicate a flood attack. Tools like intrusion detection systems (IDS) can be invaluable.
• DDoS Protection: DDoS protection services can help mitigate the effects of a flood attack. These services often use a combination of traffic filtering, rate limiting, and other tactics to ensure only legitimate traffic reaches the target. 
• Secondary DNS: If the primary DNS server becomes overwhelmed due to a flood attack, the secondary DNS server can continue to resolve domain names, ensuring that services remain accessible to legitimate users.
• Firewalls and Routers: Properly configured firewalls and routers can help filter out malicious traffic.
  Router vs firewall
• TTL Analysis: Investigate the TTL values on incoming packets. Abnormal TTLs can indicate potential malicious traffic.
• IP Blocklisting: Identify and block IPs that show malicious activity. This prevents them from accessing your systems further.
  Whitelisting vs Blacklisting

Types of flood attack

DNS Flood Attack

A DNS flood attack specifically targets the Domain Name System (DNS) servers. The DNS is the internet’s phonebook, translating human-friendly URLs (like “example.com“) into IP addresses that computers use to identify each other on the network (like “1.2.3.4”). In a DNS flood attack, attackers send a high volume of DNS lookup requests, usually using fake IP addresses. This causes the DNS servers to try and resolve each request, leading to an overwhelming number of processes. This congestion ensures that genuine requests from real users either get significantly delayed or ignored altogether. If an attacker successfully disrupts a DNS server, it can make a whole swath of websites or online services inaccessible.

SYN Flood Attack

To understand a SYN flood attack, one must first grasp the “three-way handshake” process used to establish a TCP connection. The sequence is SYN, SYN-ACK, and ACK. In a SYN flood attack, the attacker sends a rapid succession of SYN requests but either does not respond to the SYN-ACK replies or sends them from spoofed IP addresses. The target system will keep these connections open, waiting for the final ACK that never comes. This can consume all available slots for new connections, effectively shutting out legitimate users.

HTTP Flood Attack

HTTP flood attacks take advantage of the HTTP protocol that web services operate on. In this attack, a massive number of HTTP requests are sent to an application. Unlike other flood attacks, the traffic sent looks legitimate. The requests can be either valid URL routes or a mixture with invalid ones, making them harder to detect. Because the requests look so much like typical user traffic, they’re particularly difficult to filter out. This method can exhaust server resources and cause legitimate requests to time out or receive delayed responses.

ICMP (Ping) Flood Attack

ICMP, or Internet Control Message Protocol, is a network protocol used by network devices to send error messages. The “ping” tool uses ICMP to test the availability of network hosts. In a Ping flood attack, attackers inundate the target with ICMP Echo Request (or ‘ping’) packets. The target then tries to respond to each of these requests with an Echo Reply. If the attack is voluminous enough, the target system’s bandwidth or processing capabilities may get overwhelmed, causing a denial of service.

Suggeted page: The function of ICMP Ping monitoring

UDP Flood

User Datagram Protocol (UDP) is a sessionless networking protocol. In a UDP flood attack, the attacker sends many UDP packets, often with spoofed sender information, to random ports on a victim’s system. The victim’s system will try to find the application associated with these packets but will not find any. As a result, the system will often reply with an ICMP ‘Destination Unreachable’ packet. This process can saturate the system’s resources and bandwidth, preventing it from processing legitimate requests.

Impact of Flood attacks on different industries

Flood attacks can have devastating effects across various industries, each facing unique challenges and potential damages:

E-commerce:

E-commerce platforms rely heavily on their websites for sales and customer interaction. A flood attack can cause significant downtime, leading to lost sales, decreased customer trust, and potential long-term damage to the brand’s reputation. Additionally, the costs associated with mitigating the attack and enhancing security measures can be substantial.

Suggest: Global Reach, Local Touch: The Role of GeoDNS in eCommerce Expansion

Finance:

In the finance sector, the availability and integrity of online services are critical. Flood attacks can disrupt online banking, trading platforms, and payment processing systems. This not only affects customer transactions but can also lead to compliance issues and regulatory scrutiny. The financial losses and impact on customer confidence can be severe.

Healthcare:

Healthcare providers use online systems for patient management, medical records, and telemedicine. A flood attack can interrupt these services, potentially putting patient health at risk. Delayed access to medical records and appointment scheduling can cause significant operational disruptions and affect the quality of care provided.

Gaming:

The gaming industry is a frequent target of flood attacks, especially during major events or game launches. These attacks can disrupt gameplay, causing frustration among users and leading to a loss of revenue for gaming companies. The competitive nature of online gaming also means that downtime can significantly impact player engagement and retention.

Conclusion

Flood attacks are among the oldest tools in a hacker’s arsenal, but they remain effective. As the digital landscape grows and evolves, so do the methods attackers employ. Regularly updating security infrastructure, staying informed about emerging threats, and employing a proactive defense strategy can go a long way in keeping systems secure and operational.

The post Flood Attack: Prevention and Protection appeared first on ClouDNS Blog.

Secondary DNS server explained

A Secondary DNS server is a backup server that takes over the responsibilities of the Primary DNS server in case of a failure or overload. 

The backup DNS server contains the same DNS information as the Primary server, ensuring that visitors can still access your website. When a user requests a domain name, the Secondary DNS server responds with the correct IP address, just like the Primary server.

Why is a Secondary DNS server important?

Having a backup DNS server is crucial for website owners who want to ensure uptime and minimize downtime. Without a backup server, if your Primary server fails, visitors won’t be able to access your website until the issue is resolved. This could lead to a loss of revenue and reputation, especially if your website is critical to your business operations.

Moreover, having a Secondary DNS server can also help distribute the load on your Primary server. Some of the incoming traffic can be directed to the backup server, reducing the load on the Primary server and ensuring a faster response time for visitors.

How does it work?

A Secondary DNS server duplicates the DNS records of the Primary server. When a DNS query is sent, it is first sent to the Primary DNS server. Then, if the Primary server is available, it responds as usual with the requested DNS record. Yet, if it is unavailable for some reason, the DNS query is sent to the backup DNS server.

The Secondary server is configured to respond to DNS queries when the Primary server is unavailable. For that reason, it is constantly synchronized with the Primary server, meaning it automatically updates its DNS records every time the Primary server makes changes. That ensures that the backup server always has the most up-to-date DNS records.

Setting up a backup server involves configuring the Primary server to notify the backup server of any changes made to the DNS records. That is possible thanks to Zone transfer, which allows the backup server to receive updates from the Primary server.

When a Zone transfer occurs, the Primary server sends the updated DNS records to the backup server, which then updates its own DNS database with the new information. This ensures that the Secondary server always has an updated copy of the DNS data, ready to respond to incoming DNS queries.

Difference between Primary and Secondary DNS server

The main difference is hidden in the hierarchy. The Primary is the main one, and the Secondary gets the DNS records from the Primary. Let’s explain a little more about the differences between the Primary DNS server and the Secondary DNS server: 

• A Primary DNS server is the authoritative server for a particular domain. It is responsible for storing and maintaining the zone file containing all the available DNS records for that precise domain name.
• A Secondary DNS server, on the other hand, is a backup server that obtains a copy of the zone file from the Primary DNS server. It is designed to provide redundancy and improve the reliability of the DNS system. If the Primary DNS server becomes unavailable, the Secondary DNS server can take over and continue serving DNS requests.

Different configurations

There are several different Primary and Secondary DNS server configurations. We will take a closer look and explain the three most common.

Primary – Secondary

In this configuration, the current DNS server serves as a Primary DNS. All the updates of records are done to it.
The Primary DNS notifies the Secondary for changes, and then the zones are transferred through IXFR or AXFR. The Secondary DNS server serves as a backup and also reduces the load, part of the traffic goes to the Secondary.

Hidden Primary

In the current configuration, there is a DNS server behind the firewall of your company, but you would like to keep it this way. This DNS server is the primary, and you want to have it as safe as possible, and unknown for the users. The Secondary DNS server will be the one that will show your face to the world, receiving all the updates from the primary. This won’t reduce the load but is an excellent safety plan for your valuable information.

Primary – Primary

Here we have an entirely different configuration. The two DNS servers are primary. Both of them can answer to incoming DNS queries and that way they can reduce the load and act faster. The user will have the benefit of increasing speed and always having up to date data. The synchronization is made with an API in the middle between the two and keep them both updated.

No matter which configuration you choose, a Secondary DNS server can definitely benefit you. It can add extra security, better distribution of the traffic and faster results for your users. And most importantly, it is easy to set up. Even if you are using another DNS provider, you can use a Secondary DNS from ClouDNS. This way you can enjoy all the benefits and feel more relaxed about your data.

Benefits of Secondary DNS server

Here are some of the main benefits and compelling reasons why to use a backup server:

• Less downtime: It adds extra resilience to the system. It reduces unwanted outages. Even if your Primary DNS is down (due to failure, DDoS attacks, or just maintenance), the Secondary will still be running, and your users won’t be disappointed. The traffic will be managed by your Secondary DNS.
• Improved performance: You can improve the performance of the system as a whole if you distribute a part of the traffic to your Secondary DNS. This will benefit your clients, and it will result in quicker loading times for them.
• Backup plan: You can use it as a backup plan and have a copy of all the data there. Be safe. Add this extra layer of security to your system.
• Load Balancing: By distributing DNS queries across multiple servers, you can implement load balancing techniques to evenly distribute traffic and ensure optimal performance and reliability.
• Geographical Redundancy: Placing Secondary DNS servers in different geographical locations can improve the resilience of your DNS infrastructure against localized outages or network issues.

Who Needs Secondary DNS Servers?

Secondary DNS servers are essential for every company with an online presence to generate revenue or for organizations handling critical operations. They serve as backups and guarantee constant functionality in case of primary server failure or malfunction. That way, all purchases and work can proceed as normal despite an outage. Some entities that need them are:

• Businesses and Organizations: Businesses rely heavily on their online presence for various operations. A backup server ensures their website and other online services remain accessible even if the primary server fails.
• E-commerce Platforms: E-commerce platforms need high availability to process transactions and serve customers effectively.
• Internet Service Providers (ISPs): ISPs often use Secondary DNS servers to ensure uninterrupted internet service for their subscribers.
• Critical Infrastructure Providers: Entities operating critical infrastructure, such as utilities, healthcare facilities, and financial institutions, rely on Secondary DNS servers to ensure uninterrupted service delivery.
• Web Hosting Providers: Web hosting companies host thousands of websites on their servers. They typically offer Secondary DNS services to their clients to ensure the high availability of their websites.
• Government Agencies: Government agencies also require high availability of their online services. They use backup servers to ensure continuous accessibility to their websites, portals, and other online resources, even during emergencies or technical failures.

Conclusion

Having a Secondary DNS server is essential for website owners who want to ensure uptime, minimize downtime, and improve the reliability of their DNS system. It serves as a backup plan that takes over the responsibilities of the Primary server in case of failure or overload, ensuring visitors can still access your website. In addition, by distributing the traffic to the backup server, you can improve the performance of the system as a whole and enjoy quicker loading times for your users. Overall, a Secondary DNS server is a smart and easy-to-set-up solution that can benefit any website owner.

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Primary DNS server explained

The Primary DNS server is also known as Master server. It is responsible for hosting the zone file. This file contains information about the domain in forms of DNS records. Each domain can have just one Primary DNS server. You can manage the zone by those DNS records. You can add, edit or delete those records. The Primary also synchronizes its data with the rest of the servers if there are some. There are usually Secondary DNS servers who have a copy of the zone data. This helps with redundancy and guarantees more up time.

How does the Primary DNS server work?

The Primary DNS server is responsible for maintaining the authoritative copy of the DNS zone file for a particular domain. The DNS zone file contains information about the domain’s resource records, such as IP addresses, MX records, and NS records. 

When a recursive server receives a DNS query for a domain, it will search for the IP address associated with that domain. If the DNS resolver is configured to use the Primary DNS server for the domain, it will send the DNS query to that server. The Primary will then search its zone file to find the requested information and send it back to the DNS resolver, which will, in turn, return the information to the user.

The Primary is also responsible for updating the DNS zone file with any changes that occur to the DNS data. These changes can happen, for example, when creating a new DNS record or adding a new email server. Once the Primary DNS server updates the zone file, it notifies other DNS servers that it is authoritative for that domain, so they can update their own cache accordingly.

Is just a single Primary DNS server enough?

Yes, it is possible for a single Primary DNS server to be sufficient for a domain name, yet it poses a significant risk of a single point of failure. If the server experiences any issues such as maintenance, updates, power outages, or technical difficulties, there will be no backup to respond to DNS queries. Therefore, it is recommended to have a network of at least a few Secondary DNS servers that can share the load, reducing stress on the Primary DNS server and providing redundancy.

How to protect your Primary DNS?

There are different approaches for keeping your Primary DNS safe and protected.

First let’s think about the data flow. In every step, where there is a data transfer, there could be a potential threat.

1. The zone file. It can get corrupted by an accidental mistake or malicious activities. It should be secure, and you need to do a backup often. Also you will need an excellent administrator to handle it.
2. Dynamic updates. Here, significant threats are the unauthorized updates. You can limit only specific IP to be able to make such updates.
3. Zone transferring. Again, limit the IPs which can do it.
4. Remote queries. Better use a secure VPN for this kind of interaction or someone can intercept your remote queries.

The second excellent solution for guaranteeing the security and protection of your network is Secondary DNS. Once you implement it, you will have an additional set of Authoritative DNS servers for your domain name. That way, if your Primary DNS server fails and is not able to handle the incoming DNS requests for your domain, the Secondary DNS servers will handle the load, and your website or service will remain available for your clients. Secondary DNS is also known as Backup DNS due to the fact it makes a copy and stores all of the DNS data (DNS records) for your domain. So, it is a secure backup if you lose your original information.

How to use both Primary DNS and Secondary DNS?

You can use ClouDNS as your Primary DNS provider and use another company for Secondary DNS or vice versa. Just remember that you control the zone file through your Primary DNS, so better choose a provider that offers easy to use control panel and has excellent customer service.

Best Practices for Primary DNS Server Management

Let’s talk a little bit about the best practices when it comes to managing a Primary DNS server:

• Regular Backups: Performing regular backups of the Primary DNS Server’s configuration and zone files is essential. It safeguards against data loss. This practice ensures that, in the event of a server failure or other catastrophic events, administrators can quickly restore the DNS data to its previous state.
• Monitoring and Logging: Implementing comprehensive monitoring and logging tools helps administrators track the performance and health of the Primary DNS Server. Monitoring tools can provide insights into query volumes and response times and detect unusual or suspicious activities. The practice is crucial for identifying potential issues and mitigating security threats. 
• Redundancy and High Availability: To enhance reliability, administrators should configure Secondary DNS servers to provide redundancy. Secondary servers will still respond to DNS queries if the Primary DNS server becomes unavailable, which also helps minimize downtime.
• Security Measures: The security of the Primary DNS Server is paramount to prevent unauthorized access or tampering. Implementing secure practices, such as access controls, firewalls, and routine security audits, helps safeguard the integrity of the DNS records.
• Regular Updates and Patching: Keeping the DNS server software up-to-date with the latest patches and updates is crucial for handling security vulnerabilities and ensuring optimal performance. Regular updates also help incorporate new features and improvements.

Conclusion

In conclusion, the Primary DNS server is a crucial component of the DNS hierarchy, responsible for maintaining the authoritative copy of the DNS zone file for a particular domain. It plays a central role in DNS resolution, and keeping it safe and protected is essential.

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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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