What is an HTTP flood attack?

An HTTP flood attack is a form of Distributed Denial of Service (DDoS) attack specifically targeting web servers. In this malicious assault, the attacker overwhelms a web server with an enormous volume of HTTP requests, rendering it incapable of handling legitimate user requests. This tactic capitalizes on the stateless nature of the HTTP protocol, allowing for easy forging and amplification of requests. Such attacks can come from a single source or be distributed across multiple locations, making them harder to trace and block. The simplicity of executing these attacks makes them a popular tool among cybercriminals looking to disrupt online services.

How does it work?

Step 1: Request Amplification

HTTP flood attacks exploit the stateless nature of the HTTP protocol, enabling attackers to forge a vast number of seemingly legitimate requests. These requests are often designed to consume server resources disproportionately.

Step 2: Botnet Deployment

Perpetrators commonly utilize botnets, networks of compromised computers, to amplify the scale and impact of the attack. This distributed approach makes it challenging to trace and mitigate the source of the assault.

Step 3: Targeting Specific Vulnerabilities

HTTP flood attacks may exploit vulnerabilities in web server software, operating systems, or specific applications. By pinpointing weaknesses, attackers maximize the efficacy of their assault.

Types of HTTP flood attacks

In the realm of HTTP flood attacks, adversaries deploy a variety of tactics to overwhelm web servers, each with its own distinctive approach.

• GET Floods: GET Floods are a type of HTTP flood attack that targets the HTTP GET method used in web communication. Attackers send a massive number of GET requests to a web server, designed to look like legitimate user interactions, with the aim of overwhelming the server’s resources and capacity to respond. Imagine your website is a popular restaurant, and suddenly, an overwhelming number of customers flood in, each asking for the menu without any intention of placing an order. GET floods operate similarly, bombarding the server with a surge of requests for information, causing chaos and resource exhaustion.

• POST Floods:  POST Floods focus on the HTTP POST method, which is used for sending data to a server. In these attacks, cybercriminals flood the server with numerous POST requests, often containing seemingly valid data submissions. This flood of requests can strain the server’s CPU and memory resources, causing delayed responses or service disruptions. Picture customers storming in and placing orders at an unprecedented rate, without any regard for the kitchen’s capacity. POST floods emulate this scenario by inundating the server with an excessive number of data-submission requests, pushing the server to its limits and potentially causing it to stumble.

Impact of HTTP flood attack

Picture your website as a bustling city during rush hour and an HTTP flood attack as an unexpected surge in traffic causing digital gridlock. This online congestion not only disrupts normal operations but also leads to inevitable downtime and service interruptions as the server contends with an overwhelming influx of requests.

• Downtime and Service Disruption. Think of your website as a bustling city with countless residents seeking information. An HTTP flood attack is like an unexpected traffic jam, bringing the entire city to a standstill. Downtime and service disruption become inevitable as the server struggles to handle the overwhelming surge of requests.
  Suggested article: Understanding the HTTP status codes

• Financial Loss. Just as a shop loses revenue when forced to close unexpectedly, businesses hit by an HTTP flood attack experience financial setbacks. The loss isn’t just in terms of immediate revenue; it’s also about potential future earnings as user trust takes a hit.
• Reputational Damage. Consider the impact on a brand when its flagship store experiences a sudden closure. Similarly, successful HTTP flood attacks can tarnish a website’s reputation, eroding the hard-earned trust of users. Reputational damage extends beyond the immediate attack, affecting long-term relationships with customers.

5 Signs your website is under HTTP flood attack

Early detection of an HTTP flood attack is crucial for effective response. Here are technical indicators that may signal such an attack:

1. Increased HTTP Request Rates: If your web server logs show a sudden and sustained increase in HTTP GET or POST requests, especially from a range of unusual IP addresses, this could indicate an attack. Monitoring tools can be configured to alert administrators to spikes that exceed baseline levels.
2. Increased CPU and Memory Usage: HTTP flood attacks force the server to handle a massive number of requests, leading to unusual CPU and memory consumption. If your server resources are maxing out unexpectedly, this might be a sign of a flood attack.
3. Slow or Non-Responsive Website: A significant HTTP flood attack can slow down your website or make it entirely unresponsive, as the server struggles to handle the load. If your site becomes inaccessible or experiences frequent timeouts, it may be under attack.
4. Log Files Full of Repetitive Requests: When reviewing server logs, you may notice a large volume of similar requests, often with the same IP range, user agent, or request URL. This repetitive pattern is a hallmark of HTTP flood attacks, as attackers often send requests in bursts.
5. Increased Bounce Rate Without Clear Cause: When legitimate users experience a slow or non-responsive website due to an attack, they are more likely to leave. If you see a sudden increase in bounce rate without an obvious reason, an HTTP flood attack may be the culprit.

Preventive measures against HTTP flood attack

Detecting an HTTP flood attack is akin to being the vigilant lifeguard at a crowded beach.

Monitoring service

Just as a lifeguard watches the ocean for irregularities, detecting HTTP flood attacks involves monitoring for abnormal spikes in web traffic. An unexpected surge signals trouble, prompting a swift response to ensure the safety of the online “beach.” With HTTP/HTTPS Monitoring service you will be able to keep track of the performance and availability of websites, web applications, and web services.

Web Application Firewalls (WAFs)

Think of WAFs as the vigilant eye of the lifeguard tower, surveying the digital sea. These firewalls analyze incoming traffic, identifying and blocking any suspicious activity, acting as a proactive defense against potential threats.

DDoS Mitigation Services

There are services specifically designed to protect against DDoS attacks, including HTTP Floods. DDoD Protection services work by diverting traffic through their networks first, filtering out the bad traffic, and only sending the good traffic to your server.

Implement Content Delivery Networks (CDNs)

CDNs distribute your content across multiple, geographically diverse servers, so it’s closer to your users. This not only speeds up content delivery but also means that traffic is spread out and not directed at a single server, making it harder for an HTTP Flood to have an impact. In addition, at ClouDNS you can build your own CDN with our GeoDNS service. With it you can be one layer protected against these malicious attacks. 

How to create your own CDN using DNS

Creating Redundancies

Have a backup plan, or in technical terms, create redundancies. If one server or network component fails under the load, others can take over. This is like having backup generators ready in case the main power supply goes out.

Conclusion

Though HTTP flood attacks present a real and present danger to web servers, the good news is that they are not insurmountable. By staying vigilant, employing a layered security approach, and embracing both reactive and proactive defense strategies, businesses can effectively dampen the impact of these attacks. Ensuring your website’s resilience in the digital ecosystem is key, allowing you to maintain seamless operations and safeguard your digital assets against such disruptive forces.

The post HTTP flood attack – What is it and How to prevent it? 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.

SYN flood attack: Origin and Basics

In the 1990s, a man named Wietse Venema explained a certain attack method in-depth. On its surface, the concept seems innocuous enough. In a network protocol, namely TCP, a three-way handshake commences communication. Imagine this as a modern chivalry ritual between your computer and the server you want to engage with.

1. You send a SYN (synchronize) packet: “Hi, can we chat?“
2. Server sends back SYN-ACK (acknowledgment): “Sure, let’s talk.“
3. You finish with an ACK: “Cool, let’s get started.“

What SYN flood attack is?

Broadly speaking, a SYN flood attack, also referred to as a TCP/IP-based attack, is a type of Denial of Service (DDoS) attack on a system. It might be compared to an irritating prankster continuously dialing a business phone to keep the line busy and prevent legitimate callers from reaching the establishment. The attacker here sends a flood of SYN requests from either a single or multiple spoofed IP addresses to a server with the malicious intent to halt the server’s functionality to process new incoming service requests. As the server gets trapped in a vicious cycle of responding to these inexistent or half-open connections, it can lead to crashing or becoming unavailable to legitimate users.

How does it work? 

The mechanics of a SYN flood operate in a methodical sequence of steps that exploit the TCP handshake protocol. Let’s break it down for clarity:

Step 1: Identifying the Target

The attacker first picks out the target server. Usually, they’re gunning for a specific service, like a website or an application hosted on that server.

Step 2: Initiating SYN Requests

Here, the attacker commences the mischief by generating a multitude of SYN packets. Each of these SYN packets asks the server, in essence, for permission to establish a connection.

Step 3: Half-Open Connections

Upon receiving a SYN request, the server reciprocates with a SYN-ACK packet and moves the corresponding request to a backlog queue. This places the connection in a “half-open” state, awaiting the client’s final ACK for completion.

Step 4: Server Response

At this juncture, the attacker ghosts the server, never sending the final ACK to complete the handshake. Consequently, the server’s backlog queue starts brimming with incomplete handshakes.

Step 5: Resource Exhaustion

With each half-open connection, the server allocates a chunk of its resources. As these incomplete connections accrue, the server begins to hit its limit on resources.

Step 6: Denial of Service

At this point, the server becomes unable to accept any new connections. Legitimate users trying to connect encounter timeouts or failures, achieving the attacker’s endgame of denying service.

Types of SYN Flood Attacks

SYN flood attacks can take on multiple forms, each with its own level of complexity and associated risks:

1. Direct Attack: In this type of attack, the attacker does not hide their IP address, meaning that all traffic comes from a single source. This makes it relatively easier for network administrators to identify and block the attack by filtering the IP address. However, direct attacks can still overwhelm a server, especially if they come from high-capacity sources.
2. Spoofed Attack: Here, the attacker sends SYN requests using spoofed IP addresses, making it difficult to track the origin of the traffic. The server tries to send SYN-ACK packets to non-existent or unreachable IPs, leaving the connections open and slowly exhausting server resources​. Spoofing adds an extra layer of complexity, making it harder to mitigate, as simply blocking the traffic source won’t solve the problem.
3. Distributed Attack (DDoS): In a distributed SYN flood attack, the attacker uses a botnet – a network of compromised devices – to send SYN requests from various IP addresses. This creates massive amounts of traffic from multiple sources, overwhelming the server and making it extremely difficult to pinpoint and block the attack. This method was infamously used by the Mirai botnet, which leveraged IoT devices to launch one of the largest DDoS attacks in history​.

Ways to mitigate the SYN flood attack

Ah, but there’s hope! Multiple strategies can serve as lifelines in mitigating the fallout from a SYN flood.

SYN cookies

Implementing SYN cookies proves useful in minimizing risk. When deployed, the server doesn’t allocate resources right away for a new SYN request. Rather, it converts the connection into a unique cryptographic cookie. Only when the handshake gets completed does the server expend resources, reducing vulnerability to attacks.

Rate limiting

Another solid tactic involves imposing rate limiting on incoming SYN packets. By setting a strict threshold for the number of allowable new connections per unit of time, the server can effectively nip malicious flood attempts in the bud.

DDoS Protection

Incorporating DDoS protection is an advanced, indispensable strategy. These specialized solutions not only defend against SYN flood attacks but also guard against a broader range of DDoS threats. DDoS protection services usually feature large traffic scrubbing networks that can sift through immense volumes of data, allowing legitimate traffic through while blocking malicious requests.

Anycast DNS

Anycast DNS serves as another invaluable layer of defense. By distributing incoming traffic across multiple data centers (PoPs), it minimizes the load on any single server. This distribution can effectively dilute a SYN flood attack, rendering it far less potent. Anycast DNS is especially beneficial when used in conjunction with DDoS protection services, providing an additional layer of robust, scalable defense.

Robust Load balancers
High-capacity load balancers can significantly improve your system’s capacity to manage an enormous volume of connection requests. In turn, this can enhance your network’s ability to resist SYN flood attacks.

Monitoring services
Real-time Monitoring services track and scrutinize network patterns, activities, and performance, enabling the early detection of potential threats or attacks. These services can monitor server health, network performance, and traffic patterns, thereby identifying and alerting about possible anomalies that might indicate a SYN flood attack.

Firewall rules

Tweaking firewall configurations can also be invaluable. For instance, you can set rules to block incoming requests from a specific IP address if it exceeds a set number of SYN requests within a short timeframe.

Suggested article: Router vs firewall

Consequences of non-protection

• Service disruption: SYN flood attacks can result in service disruption or downtime, as the targeted server becomes overwhelmed and unable to handle legitimate requests.
• Financial loss: Downtime can lead to financial losses for businesses, especially e-commerce websites, online services, and organizations heavily reliant on internet connectivity.
• Reputation damage: Frequent DDoS attacks, including SYN floods, can tarnish a company’s reputation, eroding trust and customer confidence.
• Security overhaul costs: Post-attack, merely patching vulnerabilities won’t suffice. A complete revamp of security protocols becomes vital, often draining both time and financial resources.

Conclusion

In a world increasingly reliant on digital technology, understanding and defending against threats like SYN flood attacks is crucial. While they are a potent threat, solutions such as SYN cookies and robust load balancers offer effective means of mitigation. In essence, maintaining cybersecurity is not just a good idea, but a necessity in today’s digital landscape.

The post Understanding SYN flood attack appeared first on ClouDNS Blog.

Understanding Enterprise DNS

Enterprise DNS is an advanced DNS service designed to meet the unique needs of large companies and organizations. It extends far beyond the capabilities of traditional DNS plans and services. It offers custom-tailored solutions to handle the extensive demands of modern businesses with expansive networks. Enterprise DNS ensures optimal domain name resolution, load balancing, and advanced traffic management, enhancing the reliability and performance of network services for these companies. It delivers the scalability and customization necessary to handle the complex and high-demand DNS needs of large enterprises. That way, it contributes to smoother online operations and improved user experiences.

Who needs Enterprise DNS?

Enterprise DNS is a must for various types of businesses and organizations, each with its own specific requirements. Here are some key players who can benefit from investing in Enterprise DNS solutions: 

• Large Enterprises: Big corporations with extensive online presence, multiple departments, and a global customer base mainly aim for Enterprise DNS. These organizations require highly available, fault-tolerant, and scalable DNS solutions to ensure their online services are always accessible. This service helps them efficiently handle large volumes of traffic and distribute it across multiple servers, ensuring minimal downtime.
• Big e-commerce sites. Having a huge shop means countless requests all the time. You need a network of DNS servers that can handle the traffic and offer fast speed to your customers, regardless of their current location. 
• Mission-critical applications. It is a must-have for all those applications that can’t afford even the shortest downtime. For some organizations, bad DNS can completely stop them and lead to severe problems. Imagine companies that provide power grid management or public transport. 
• Online Service Providers: Companies offering cloud-based or Software as a Service (SaaS) solutions must guarantee uninterrupted service to their customers. With Enterprise DNS and directing traffic to the closest servers, they can significantly improve the user experience and minimize latency.
• Content Delivery Networks (CDNs): CDN providers highly rely on the advanced DNS capabilities. Enterprise DNS is really valuable in delivering the needed content quickly and efficiently to users all around the world.

Benefits of using Enterprise DNS

Enterprise DNS services are usually the top-of-the-line ones. They gathered the benefits of the rest and packed them inside a special plan that best suits big companies. It provides a range of benefits, including:

• High Availability: Redundancy and failover mechanisms ensure that your services remain online even in the face of server or network failures.
• Maximum Speed: By directing users to the nearest servers, this service is able to provide the highest speed. As a result, it reduces latency and improves the user experience.
• Protection: The Enterprise solution offers advanced security measures to protect against DDoS attacks, data breaches, and other online threats.
• Scalability: It is designed to handle growing traffic and can be easily scaled to meet the increasing demands of your organization.
• Global Reach: Enterprise DNS can ensure seamless traffic management across different regions for businesses with a global presence.

Enterprise DNS by ClouDNS

The Enterprise DNS service provided by ClouDNS provides an advanced solution for our large clients. It offers the following features and advantages:

• 100% DNS availability. We provide excellent uptime thanks to our Anycast DNS that has 50+ servers, set in important parts of the world. If one is down, there still will be the rest available that can handle the traffic. 
• Administrate more than 20,000 DNS records in a single DNS zone. Our system can administrate many DNS records. We have clients who use Enterprise DNS to create DNS-based Black Lists with 300000+ DNS records.  
• Immediate propagation. You can manage and monitor the domain propagation through our web-based control panel. You can lower the TTL values down to 1 minute and have zero downtime while doing it.  
• DDoS Protection. Every year the situation with DDoS attacks is getting worse. We developed our DDoS protection back in 2014, and since then, we have significantly improved it.
• Great speed. To achieve it, we have created an Anycast network of 50+ servers. Your clients will get their queries resolved from the closest. The speed will be excellent, no matter if your clients connect from Africa or North America.  
• White-label DNS and dedicated IPs. We work with many Internet providers, hosting companies, and telecoms. White-label DNS lets you use our services and integrate them into yours. That way, you can add excellent DNS services without the need for your own infrastructure. 
• Excellent 24/7 support. And of course, we provide constant support over live chat and also tickets system. We are always online to assist you with your needs. 

How to Get Started?

Getting started with Enterprise DNS from ClouDNS is simple and easy. To begin, we recommend visiting our dedicated Enterprise DNS page, where you can explore the full range of features and benefits designed for large-scale businesses.

For all of your specific requirements or questions, make sure to contact our expert sales team, which is ready to assist you and is happy to help. They can provide tailored solutions based on your organization’s unique needs, ensuring the perfect match for your DNS requirements. Whether you’re looking for improved speed, enhanced security, or scalable infrastructure, ClouDNS has the expertise to help your business thrive online.

Contact our sales team today and let us help you get the perfect DNS solution for your business and your growing infrastructure!

Conclusion

If you need an Enterprise DNS, one that won’t let you down, ClouDNS is here for you. We won’t limit your queries, and we will provide Anycast servers for great traffic handling and excellent speed. 

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

Botnet – What does it mean?

A Botnet is a network of different devices, like computers, smartphones, tablets, and IoT, which are infected with malware and controlled by a cyber-criminal, also known as a bot herder. Each individual device within the botnet network is also known as a bot or zombie.

These hijacked devices are utilized to carry out different scams and cyberattacks, like sending spam emails, distributing malware, and preparing DDoS attacks. The assembly of a botnet is usually the infiltration step of a multi-layer scheme. Botnets employ the devices of regular users for scams and disruptions without requiring the permission of the owner.

DDoS Protected DNS Service

You are probably wondering what the botnet attack actually is and how it works. So, let’s expand the topic and clarify for what purposes they are used!

What are botnets used for?

There are different reasons why attackers use botnets. However, the most popular intentions are related to stealing data and money. Here are some of the most common usages of the networks of hijacked devices:

Fraudulent or money stealing

Cybercriminals can perform attacks that involve a botnet network for stealing money directly or indirectly. Some of the popular methods to achieve that are phishing emails or making a fake website that looks exactly like the original bank website, for example. Then, they are able to translate the payment or transaction details and utilize them to steal money.

Data theft

The data of the users is highly valued in the market. Cybercriminals are well aware of that. Therefore, they use botnets for stealing individual personal information, or even more, they break into the database of a precise company. The next step for them is to sell the user information to third parties and make a profit from it. These botnets could stay inactive and only steal personal details.

Perform spamming and phishing frauds

By implementing botnets, attackers can execute large email spamming and phishing scams. That is because they can spread malicious emails to numerous targets easily. Moreover, there are spam botnets that are precisely designed for such tasks.

However, the intentions are always the same, meaning stealing money or information, even if the methods differ. Yet, there are a specific group of cybercriminals who use botnets only because they can. They only aim to show their abilities and demonstrate their superiority to the rest of the world. There are different examples of security breaches where the attackers steal personal details and reveal them on the dark web for free.

Botnet attack – explained in detail

We talk about a Botnet attack when cybercriminals inject malware into the network to control them as a collective used for initiating cyberattacks. Otherwise, botnets themselves are simply a network of devices. 

The scale of a Botnet attack could be pretty large, and any device could fall victim to it. So, cybercriminals use additional machinery or devices to support and improve the mastership of a botnet.

Bot herder is needed to guide and control the group of hijacked devices in the network. The attacker uses it via remote commands to guide the devices and make them complete specific actions.

Bot or zombie computer is an infected device (system) used to create a botnet. The bots are guided by the bot herder’s command, and they behave by its instructions.

Let’s break down the construction process of a Botnet attack. Here are 3 main steps you should know:

Step 1: Prep and Expose

The cybercriminal discovers a vulnerability to introduce into the user’s device. The process of searching for a vulnerability involves the website, human behavior, and application. That way, the attacker prepares a set-up to drown the victim to get exposed to malware without notice. Typically, the vulnerabilities are found in websites and software, and the malware is delivered through emails or messages.

‍Step 2: Infecting the user

The attacker activates the malware, and the user’s device is infected and has compromised security. Typically, for that purpose, cybercriminals use the social engineering method or the Trojan virus. Another more aggressive approach includes deploying drive-by-download strategies to infect the device. However, with all of these methods, cybercriminals aim to weaken the target with botnet malware.

‍Step 3: Taking control over the targeted devices

The last step is taking control of each infected device. All of them are systematized, and the attacker involves a method for managing them remotely. Numerous devices are under control through a massive zombie network. After completing this step, the cybercriminal gains admin-like access to the targeted devices. Moreover, it has the ability to read and change the stored information, capture it, share it, or watch all of the activities on the device.

Most popular Botnet attack types

Botnets are attacks by themselves also, but they are a perfect instrument for performing secondary frauds and cybercrimes on a giant scale. Here are the most popular Botnet attack types:

DDoS attack

DDoS attacks aim to overwhelm a target server, network, or device with massive traffic. The zombie devices (bots) send large amounts of requests aiming to crash or at least slow down the target significantly.

That is one of the most popular forms of using botnets for criminal purposes. Additionally, it is commonly the one that is the most dangerous. The negative effects of DDoS attacks are often long-term and severe. That includes not only financial losses but also reputational damages for the target organization.

That is critical for everyone that has a functional website and especially for businesses that operate and offer their services online. So for sure, proper DDoS protection is a must! Unfortunately, it is already too late for you to plan your response when a DDoS attack appears. Therefore, protection and mitigation should be planned.

Phishing

Botnet attacks are commonly built by phishing tactics. That way, they infect more devices and extend the size of the botnet.

Additionally, phishing and other methods of social engineering attacks include a botnet that sends emails, posts comments or sends messages on social media acting like people or businesses that the victim trusts, commonly used to steal your banking details.

Precisely phishing is hard to defend against because humans easily fall victim to them.

Brute Force attack

Another popular way that bot headers use botnets is to complete different Account Takeover (ATO) attacks, mostly Brute Force attacks (credential cracking).

For a Brute Force attack, the zombie devices are instructed to test the various options of a user password and “crack” it. For instance, if there is a PIN with 4 digits, bot device 1 is going to test “0000”, the second bot device is going to test “0001”, etc. That continues until one of them guesses the correct PIN.

Defending against this botnet attack is also very challenging. It is effective in exploiting weak user credentials.

Which devices can become targets of a Botnet?

Devices infected with malware, also known as “bots” or “zombies,” can be remotely controlled by attackers. Almost any device with an internet connection can potentially become a target for a botnet if it has vulnerabilities that can be exploited. Here are some common types of devices that can be targeted:

• Personal Computers: Desktops and laptops running various operating systems, including Windows, macOS, and Linux, can be targeted by botnets if they have security vulnerabilities. Malware can infect these devices through malicious downloads, email attachments, or drive-by downloads.
• Servers: Web servers, email servers, and other types of servers are attractive targets for botnets because they often have high-speed internet connections and large resources. Compromised servers can be used to host malicious content, launch DDoS attacks, or distribute malware.
• Mobile Devices: Smartphones and tablets are also exposed to botnet infections. Malicious apps, compromised app stores, and phishing attacks can be used to target these devices. Both Android and iOS can be affected by botnet-related threats.
• IoT Devices: Internet of Things devices, such as smart cameras, smart thermostats, routers, and smart appliances, are targeted by botnets. They are often less protected and may have default or weak passwords, making them easy targets for exploitation.
• Network Equipment: Routers, switches, and other devices can be compromised by botnets. Once infected, these devices can be used to control network traffic, redirect users to malicious websites, or participate in DDoS attacks.

Signs your device could be part of a Botnet

Here are the most common signals that your device could be part of a Botnet:

• Unusual Sluggishness: If your device suddenly becomes slow or unresponsive, it may be because a botnet is using its resources.
• Excessive Data Usage: A sudden spike in data usage without an apparent reason could indicate your device is participating in botnet activities.
• Unwanted Pop-ups: Frequent pop-up ads or redirects to suspicious websites may signal that your device is under the control of a botmaster.
• High CPU Usage: Constantly high CPU usage, even when you’re not running intensive applications, can indicate malicious activity.
• Outbound Spam Emails: If your email contacts receive spam from your account without your knowledge, your device may send spam as part of a phishing attack.
• Disabled Security Software: Malware in a botnet often tries to disable antivirus and firewall protection to avoid detection.
• Unexplained Software Installs: Unauthorized software installations or changes to your device’s settings can be a sign that attackers may have control over it.
• Strange Network Activity: Monitor your network traffic for unusual patterns, such as frequent connections to unfamiliar IP addresses or domains.

How to protect yourself?

Here are some things you can do to protect yourself from botnet malware.

• Strong passwords. Make sure all of your smart devices have complex long passwords. That will keep them safer compared to a short and weak password, like “123456”.
• Update your OS. You should update your software. That way, you are receiving all of the security patches that can deal with familiar vulnerabilities.
• Change admin settings and passwords across all of your devices. Make sure to check all potential privacy and security options. That includes everything that connects device-to-device or to the Internet. If you skip changing to custom login credentials and private connectivity, cybercriminals will be capable of breaching and infecting all of your devices.
• Avoid opening suspicious email attachments. Before you download a file, make sure to verify the sender’s email address.
• Avoid clicking on links in messages. Different texts, emails, or social media messages could include malware. Moreover, by doing so, you can avoid drive-by downloads and DNS cache poisoning.
• Reliable antivirus software. It is going to help you improve your security and keep yourself protected from Trojans and other threats.

Impact of Botnets on Businesses

Botnets are a growing threat to businesses of all sizes, exploiting weak spots in networks to carry out malicious activities. Here’s a breakdown of how they can impact your business:

• Financial Losses

Botnets can cause serious financial damage. They might steal sensitive data directly, demand ransoms after launching ransomware attacks, or disrupt your services, leading to lost revenue. For example, a Distributed Denial of Service (DDoS) attack could take down your website, resulting in significant downtime and a drop in productivity.

• Damage to Your Reputation

The impact of a botnet attack goes beyond immediate financial losses. It can also severely damage your company’s reputation. Customers and partners may lose trust in a business’s ability to protect confidential information, resulting in long-term loss of clientele. There could also be legal consequences if your company fails to comply with data protection laws. Recovering from such an attack often requires significant investment in cybersecurity measures, system restorations, and efforts to rebuild public trust.

• Increased Operational Costs

Botnet infections can also lead to the unauthorized use of company resources, increasing operational costs and exposing internal systems to even more security risks. Small and medium-sized businesses are especially vulnerable, as they might not have the necessary infrastructure or expertise needed to effectively defend against these threats.

To reduce the risk of botnet attacks, it’s essential to adopt proactive security measures and include regular employee training, robust incident response plans, and a strong focus on cybersecurity. By taking these steps, you can help protect your business from the negative effects of these attacks.

Some famous Botnet attacks

Mirai – 2016

The massive Mirai botnet attack was initiated through a DDoS attack, and it made the Internet unavailable in the U.S. It was the first major botnet that infected insecure IoT devices. At the peak of the attack, it got to over 600,000 infected devices. 

3ve – 2018

3ve, pronounced Eve, started as a small botnet. Yet, the number of infected devices reached a tremendous 1.7 million. The botnet managed to falsify billions of ad views. As a result, businesses paid millions for ads that no real human, a regular internet user, ever saw.

Conclusion

Botnet and Botnet attacks are cyber threats that should not be neglected! It is important to keep yourself or your organization safe from such malicious attempts. Otherwise, they could lead to large financial and reputational damages!

The post Botnet – what is it, and how does a Botnet attack work? 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.

It helps determine if the transferred data is reaching its target destination on time. For that reason, ICMP is an essential element when it comes to the error reporting process and testing. However, it often gets utilized in DDoS (Distributed Denial-of-Service) attacks.

History of ICMP

The ICMP protocol was conceived as a vital component of the Internet Protocol Suite, introduced in 1981 with RFC 792. Its origins can be traced back to the early days of the internet when the need for a diagnostic and error-reporting tool was identified. Over the years, ICMP has experienced several refinements, with additional message types being introduced. Its fundamental purpose of providing feedback about issues related to datagram processing has remained consistent throughout, making it an indispensable tool for network diagnostics.

What is ICMP protocol used for?

The ICMP protocol could be used in several different ways. They are the following:

The main purpose of ICMP is to report errors

Let’s say we have two different devices that connect via the Internet. Yet, an unexpected issue appeared, and the data from the sending device did not arrive correctly at the receiving device. In such types of unpleasant situations, ICMP is able to help. For instance, the problem is occurring because the packets of data are too large, and the router is not capable of handling them. Therefore, the router is going to discard the data packets and send an ICMP message to the sender. That way, it informs the sending device of the issue.

ICMP is commonly used as a diagnostic tool

It is used to help determine the performance of a network. The two popular utilities, Traceroute and Ping, operate and use it. They both send messages regarding whether data was successfully transmitted.

• The Traceroute command is helpful for displaying and making it easy to understand the routing path between two different Internet devices. It shows the actual physical path of connected routers that handle and pass the request until it reaches its target destination. Each travel from one router to another is called a “hop.” The Traceroute command also reveals to you how much time it took for each hop along the way. Such information is extremely useful for figuring out which network points along the route are causing delays.
• The Ping command is similar, yet a little bit more simple. It tests the speed of the connection between two different points, and in the report, you can see precisely how long it takes a packet of data to reach its target and return to the sender’s device. Despite the fact that the Ping command does not supply additional data about routing or hops, it is still an extremely beneficial tool for estimating the latency between two points. The ICMP echo-request and echo-reply messages are implemented during the ping process.

Cybercriminals utilize it too

Their goal is to disturb the normal network performance. They initiate different attacks, such as an ICMP flood, a Smurf attack, and a Ping of death attack. Attackers are determined to overwhelm the victim and make the standard functionality not possible.

How does it work?

Internet Control Message Protocol stands as one of the leading protocols of the IP suite. Yet, it is not associated with any transport layer protocol, for instance, Transmission Control Protocol (TCP) or User Datagram Protocol (UDP).

ICMP is one of the connectionless protocols, which means that a sending device is not required to initiate a connection with the receiving party before transmitting the data. That is why it differs from TCP, for instance, where a connection between the two devices is a mandatory requirement. Only when both devices are ready through a TCP handshake, a message could be sent.

All ICMP messages are sent as datagrams and include an IP header that holds the ICMP data. Each datagram is a self-contained, independent entity of data. Picture it as a packet holding a portion of a larger message across the network. ICMP packets are IP packets with ICMP in the IP data part. ICMP messages also include the complete IP header from the original message. That way, the target system understands which precise packet failed. 

ICMP Packet Format

ICMP is designed to be used within IP packets. When an ICMP message is sent, it is encapsulated within an IP packet, and the ICMP header follows the IP header within that packet.

In the ICMP packet format, the first 32 bits of the packet are divided into three fields:

Type (8-bit): The initial 8 bits of the packet specify the message type, providing a brief description so the receiving network knows the kind of message it is receiving and how to respond. Common message types include:

• Type 0: Echo reply
• Type 3: Destination unreachable
• Type 5: Redirect Message
• Type 8: Echo Request
• Type 11: Time Exceeded
• Type 12: Parameter problem

Code (8-bit): The next 8 bits are for the code field, which provides additional information about the error message and its type.

Checksum (16-bit): The last 16 bits are for the checksum field, which checks the number of bits in the complete message to ensure that all data is delivered correctly.

Extended Header (32-bit): The next 32 bits of the ICMP header are the Extended Header, which points out issues in the IP message. Byte locations are identified by the pointer which causes the problematic message. The receiving device uses this information to pinpoint the issue.

Data/Payload: The final part of the ICMP packet is the Data or Payload, which is of variable length. In IPv4, the payload includes up to 576 bytes, while in IPv6, it includes up to 1280 bytes.

Types and codes in ICMP

ICMP messages are distinguished by their type and, in some cases, a code to further specify the nature of the message. There are numerous types, each serving a unique purpose. A few common types include:

• Echo Reply (Type 0): A response to an echo request, commonly used in ping.
• Destination Unreachable (Type 3): Indicates that the destination is unreachable for some reason. Various codes further specify the reason, such as network unreachable (Code 0), host unreachable (Code 1), or protocol unreachable (Code 2).
• Redirect (Type 5): Informs the host to send its packets on an alternative route. The accompanying codes provide more details, like redirect for the network (Code 0) or redirect for the host (Code 1).
• Time Exceeded (Type 11): Generated when a packet takes too long to transit a network or when reassembly time is exceeded.

These are just a few examples, and there are many other types and codes in the ICMP specification that serve various purposes.

Configuring ICMP on routers and firewalls

Configuring ICMP settings on routers and firewalls is essential to either allow ICMP traffic, prioritize it, or block it to enhance security. Here’s a brief guide:

On Routers:

1. Access the router’s admin panel, usually through a web interface or command line.
2. Navigate to the advanced settings or firewall settings.
3. Look for an option related to ICMP or ‘Ping Request’ and either enable or disable it as required.

On Firewalls:

1. Open the firewall management interface.
2. Search for a rule or setting related to ICMP traffic.
3. Modify the rule to allow, block, or prioritize ICMP traffic based on your needs.

It’s crucial to consult the router or firewall’s documentation or seek expert advice, as incorrect configurations might result in network vulnerabilities or communication problems.

Router vs firewall, can you guess which is better?

ICMP Port?

As we mentioned earlier, the Internet Control Message Protocol is a part of the Internet protocol suite, also known as the TCP/IP protocol suite. That means it relates only to the Internet Layer. Port numbers are only found in the Transport Layer, which is the layer above.

Although Internet Control Message Protocol does not implement the concept of ports like TCP and UDP, it utilizes types and codes. Typically employed ICMP types are echo request and echo reply (used for Ping) and TTL (time-to-live) exceeded in transit (used for Traceroute).

What is ICMP Ping?

The ICMP echo request and the ICMP echo reply messages are also known as ping messages. Ping command is a beneficial troubleshooting tool that system administrators use to test for connectivity between network devices manually. They also use it for examining for network delay and loss packets.

ICMP Ping is especially useful for performing Ping Monitoring. It works by frequently pinging a precise device. This type of check sends an ICMP echo request to a specific server or device on the network, and the device instantly answers with an ICMP echo reply. That means the connection is successful, and the target server or device is up and running without any issues. 

In case the ping time, which is measured in milliseconds (ms), is prolonged, that is a sure sign of some network issues. 

ICMP vs TCP

The Internet Control Message Protocol, or ICMP, has a completely different function compared to TCP (Transmission Control Protocol). Unlike it, ICMP is not a standard data packet protocol. Moreover, it is a control protocol, and it is not designed to deal with application data. Instead, it is used for inter-device communication, carrying everything from redirect instructions to timestamps for synchronization between devices. It is important to remember that ICMP is not a transport protocol that sends data between different devices.

On the other hand, TCP (Transmission Control Protocol) is a transport protocol, which means it is implemented to pass the actual data. It is a very popular protocol, thanks to its reliability. TCP transfers the data packets in a precise order and guarantees their proper delivery and error correction. Therefore, the Transmission Control Protocol finds its place in many operations, including email and file transfers. It is the preferred choice when we want to ensure ordered, error-free data, and speed is not the top priority.

Suggested page: What TCP monitoring is?

ICMP in IPv6 (ICMPv6)

With the growing adoption of IPv6, ICMP has also evolved to cater to the needs of the newer IP protocol. ICMPv6, introduced with RFC 4443, is more than just an adaptation; it incorporates various features and functionalities tailored for IPv6. For instance:

• Neighbor Discovery Protocol (NDP): ICMPv6 includes NDP, replacing the ARP (Address Resolution Protocol) used in IPv4, facilitating the discovery of neighboring devices.
• Router Solicitation and Advertisement: ICMPv6 aids in the discovery of routers in a network and can solicit advertisements from them.
• Enhanced Error Reporting: ICMPv6 offers more detailed feedback, facilitating improved troubleshooting in IPv6 networks.

As the internet continues its transition from IPv4 to IPv6, the importance and relevance of ICMPv6 will only grow, making it vital for network professionals to familiarize themselves with its intricacies.

Suggested article: IPv4 vs IPv6 and where did IPv5 go?

How is ICMP used in DDoS attacks?

DDoS (Distributed Denial-of-Service) attacks are extremely popular cyber threats. They are initiated with the main goal to overwhelm the victim’s device, server, or network. As a result, the attack prevents regular users from reaching the victim’s services. There are several ways an attacker can utilize ICMP to execute these attacks, including the following:

• ICMP flood attack

ICMP flood, also commonly called Ping flood attack, attempts to overwhelm the target device with ICMP echo request packets. That way, the victim device is required to process and respond to each echo request with echo reply messages. That consumes all of the existing computing resources of the target and prevents legitimate users from receiving service.

The basics of flood attacks

• Ping of death attack

The Ping of Death attack appears when a cybercriminal sends a ping larger than the maximum permitted size for a packet to a victim device. As a result, the device crashes. The large packet is fragmented on its way to the victim. However, when the device reassembles it into its original, the size exceeds the limit and causes a buffer overflow. 

The Ping of Death is considered a historical attack that does not appear anymore. Yet, that is not completely true. Operating systems and networking equipment that is more aged could still become a victim of it.

• Smurf attack

The Smurf attack is another common threat where the cybercriminal sends an ICMP packet with a spoofed source IP address. The network equipment responds to the packet and sends the replies to the spoofed IP, which floods the target with large amounts of ICMP packets. 

Just like the Ping of Death attack, the Smurf attack should not be disregarded. Unfortunately, in a lot of different companies and organizations, the equipment is a bit aged, and the threat is real!

Conclusion

The ICMP (Internet Control Message Protocol) is an incredible network layer protocol that allows devices to report errors and improve their communication. Moreover, it is a great tool for network diagnosis. It is not a surprise that a lot of administrators use it daily for a better understanding of their network with the popular utilities Ping and Traceroute. Even more beneficial is the Ping monitoring, which completes regular checks. Lastly, keep in mind to take proper supervision of your network, so it stays protected from DDoS attacks that utilize the protocol for malicious purposes.

The post What is ICMP (Internet Control Message Protocol)? appeared first on ClouDNS Blog.

What is a DDoS amplification attack?

These attacks usually use the UDP protocol. It is a simple connectionless communication model with a minimum protocol mechanism. This means that one of the sides in the communication can send large amounts to the other without restrictions. Without any confirmation, it doesn’t matter if the second side receives the data. 

Due to the way the UDP protocol works, cyber-criminals use it to generate DDoS amplification attacks. The attacker sends a small UDP request with a spoofed IP address of the victim to public services.

The UDP protocol doesn’t require a connection verification between the parties. This is why the public services reply with the requested data to the IP address of the victim. As bigger is the data returned by exploited public service, bigger is the DDoS amplification factor.

In the past few years, hackers have exploited many public DNS resolvers and NTP servers to generate massive DDoS attacks against popular websites and services.

Understanding Memcached

Memcached is a widely-used, open-source caching system that enhances the performance of dynamic web applications by reducing database load. It achieves this by storing data in memory, allowing for rapid retrieval and minimizing the need for repeated database queries. By caching frequently accessed objects such as database query results and session data, Memcached helps applications run more efficiently and respond faster to user requests. Its straightforward design and robust performance have made it a staple in optimizing large-scale web applications. However, without proper configuration and security measures, Memcached can become vulnerable to exploitation, emphasizing the need for diligent management.

Memcached DDoS amplification attack explanation

A Memcached DDoS amplification attack is a malicious exploit where attackers leverage vulnerable Memcached servers to generate overwhelming traffic towards a target. By sending small requests to multiple servers, the attackers receive significantly larger responses, resulting in an amplification effect. This massive traffic surge can cripple the target’s network infrastructure, disrupting service. To mitigate such attacks, organizations should secure their Memcached servers, implement access controls, and utilize robust DDoS mitigation solutions to protect against this highly impactful cyber attack.

How does it work? Step-by step 

1. Identifying vulnerable servers: Attackers scan the internet to locate Memcached servers that are accessible and have User Datagram Protocol traffic enabled. UDP is preferred due to its connectionless nature, making it easier to spoof source IP addresses.

By default Memcached works with enabled UDP support on port 11211. To understand this attack we have reviewed the source code of the database on GitHub.For some reason in the communication settings of the defined a fixed payload of 1400 bytes for the UDP packets.

The basic UDP request sent to Memcached is with size 15 bytes, and the server responds with 1400 bytes. This makes the amplification factor more than 93x! That amplification factor means that with a single server with 1Gbps port and a significant amount of vulnerable servers, the attacker can generate DDoS attacks over 90 Gbps.

2. Spoofing the source IP address: Using various techniques, attackers disguise their own IP address and make it appear as if the attack traffic originates from the targeted victim’s IP address. This ensures that the amplified response traffic is directed towards the victim.

Suggested article: What is DNS Spoofing (DNS poisoning)?

3. Sending small forged requests: Attackers send lightweight and innocuous-looking requests to the vulnerable Memcached servers. These requests typically have a small size, often around 15 bytes, which minimizes the effort required to send them.

4. Amplification of response traffic: Exploiting the Memcached servers’ behavior, which responds to small requests with much larger responses, the attackers achieve an amplification factor that can reach staggering levels. This means that for each small request sent, the server responds with a significantly larger volume of data, often in the range of hundreds or thousands of times larger.

5. Overwhelming the target: The amplified response traffic, generated by the Memcached servers, floods the victim’s network infrastructure with an immense volume of data. This flood of traffic can quickly exhaust the victim’s network bandwidth, computing resources, and cause service disruptions or complete downtime.

How big can it be?

In the realm of cybersecurity, we have witnessed an unprecedented magnification factor, reaching an astonishing 51,200 times the original request size! Picture this: a mere 15-byte request has the potential to unleash a colossal 750 kB response. This mind-boggling amplification factor poses an immense security risk, particularly for web properties ill-equipped to handle the overwhelming deluge of attack traffic. With its significant amplification potential and susceptible servers, Memcached becomes a prime target for malicious actors intent on launching devastating DDoS attacks against a wide array of targets.

Furthermore, according to the GitHub’s February 28th DDoS Incident Report, the largest open source code web service was down due to a Distributed Denial of Service attack that caused intermittent unavailability of their service for a few minutes. The attack exploited a vulnerability in Мemcached, resulting in a volumetric attack that peaked at 1.35Tbps. GitHub successfully mitigated the attack by diverting traffic to Akamai and implementing access control measures, and they are working on improving their automated intervention and expanding their edge network to enhance resilience against future attacks.

How to protect from Memcached DDoS amplification attacks?

Our Anycast Network is protected from such attacks, and we already mitigated more than 20 attacks like this for the last five days.

Тo protect your website, online service, etc you can also implement DDoS protection software. ClouDNS DDoS Protected DNS service can help identify and filter out malicious traffic, thereby minimizing the impact of amplification attacks.

Other way to protect from Memcached DDoS amplification attacks is by regularly monitoring the traffic. We provide robust monitoring solutions which enable the timely detection of abnormal traffic patterns, facilitating early response and mitigation.

Furthermore, with enough network capacity, we can easily filter the attack of the Memcached server responds from UDP port 11211. We can say for sure that all our customers are protected and safe.

The average size of the DDoS attacks we filter was between 50Gbps and 80Gbps. First we expect that value to grow in the next two weeks. Then to drop significantly because the system administrators will take care of the vulnerable servers.

DDoS Protected DNS

Ways to secure a Memcached server

The system administrators of Memcached servers can protect them in one of the following ways:

• Update the configuration of the server to listen only on 127.0.0.1 (localhost). Do this if use the Memcached server only locally and there are no external connections to the server. You can do this with the option –listen 127.0.0.1
• Disable UDP support, if you are not using it. You can do this with the option -U 0
• Add firewall for UDP port 11211, if you need both external connections and UDP support, make sure the server is accessible only by the IPs you need
• Instead of exposing your Memcached server directly to the internet, you can use a caching proxy server
• Restrict access to the Memcached server using access control lists (ACLs) to allow only trusted IP addresses.

Conclusion

By exploiting vulnerable Memcached servers, attackers can unleash a massive flood of traffic, causing widespread disruptions. To defend against these attacks, organizations must secure their Memcached servers, implement strict access controls, and utilize effective DDoS mitigation solutions.

The post DDoS amplification attacks by Memcached appeared first on ClouDNS Blog.

Smurf attack definition

The name Smurf comes from a popular Belgium comics and cartoon with the same name. There are many small blue characters in it who work together to bring down one big bad magician.

The Smurf DDoS attack is a protocol-based DDoS attack that uses the popular Internet Control Message Protocol (ICMP) to send ping packets of data with a spoofed IP address of the source, thanks to malicious software.

The packets are sent to a computer network using an IP broadcast address. The devices on that network will respond and send answers to the IP address. The fact that not only one computer but a whole network of computers respond to the victim’s IP address leads to a substantial amplification and potentially huge traffic towards the victim. So strong that it could severely slow down the victim’s computer and even bring it down for a while.

And you know, downtime means losses for the business.

How does a Smurf attack work?

1. The malicious Smurf software spoofs the packets’ IP address and replaces it with the victim’s IP address. That way, all the traffic will go to it.
2. The packets of data are sent to a broadcast IP address of a router. That way, the router will send the message to all the connected devices inside this broadcast network, and the attack will get amplified many times. So many times as there are devices that respond.
3. Each of the devices will receive the packets of data. They will respond but to the spoofed IP address (the target’s IP address). So the traffic will go directly to the victim.
4. The target starts to receive packets of data that it didn’t ask for. One after another, and if there are too many, the target starts to have problems processing them. Eventually, if the intensity does not go down, the target will be unable to process the pings and be overwhelmed.

What is the history of Smurf attacks?

Dan Moschuk (a.k.a. TFreak), a popular hacker at the time, created the original code for the malware in 1997. Dan was still an adolescent at the time. He sent the original software to some of his friends, and later the smurf.c crashed various IRC servers.

Because of the Smurf attack, network equipment producers started to change the settings of their devices and limit broadcasting to only inside the LAN.

Some years later, TFreak continued his work in malicious software and created a UDP version of the Smurf attack and called it Fraggle.c.

Types of DDoS Smurf attack?

There are two main types of Smurf attack:

Basic Smurf attack

The Basic Smurf attack works, just as we explained to you, flooding a network with ping packets that have spoofed the IP address of the victim. Then, all the devices on the network answer the packets and send the answers to the target, causing massive traffic that can bring down the system over time.

Suggested article: What is flood attack?

Advanced Smurf attack

It looks similar to the Basic Smurf attack but with a small difference. The Advanced can spoof the IP addresses of the packets in a way that it can send the response to more than one target. When the attackers have infected enough networks, they can use this amplified traffic to multiple victims to cause more damage.

How do you detect it?

Detecting a Smurf attack can be a difficult task. ICMP monitoring is a crucial tool when it comes to catching this attack. ICMP is an Internet Control Message Protocol that sends an alert if it detects an attack. This type of monitoring allows for real-time analysis of any suspicious activities, allowing for faster detection and mitigation of any damage caused by a Smurf attack. To set up ICMP monitoring, it is essential to set a threshold based on your network’s typical performance. Once a traffic spike that exceeds the threshold is detected, your IT team can act accordingly. ICMP monitoring provides an efficient and effective way to detect a Smurf attack promptly.

How to mitigate Smurf DDoS attack?

There are 3 things that you can do to mitigate a Smurf attack:

Use DDoS protection

Having a large network of servers means your servers can resist stronger traffic. When you combine it with an intelligent traffic monitor that can find the malicious traffic and a network of scrubbing centers, you will have excellent protection against this type of DDoS attack.

If you want to try it out, you can see our DDoS protection plans right here. Stay safe and keep your business running, lowering the downtime to a minimum.

Forbid the ICMP traffic

You can use your firewall and stop the ICMP traffic completely. This will make it impossible to suffer a Smurf attack or any other DDoS attack based on the ICMP. The problem is that you won’t be able to use a ping command for diagnostics. This could be problematic for administrators who need to check if all of the devices on a network or remote servers are connected and working, so this might not be an option for most people.

Stop packets with a broadcast IP address

You can also set up all your hosts and routing devices to ignore packets that have a broadcast IP address. That way, even if a modified Smurf attack packet gets to your network, it won’t be allowed. If you don’t need to broadcast any other messages, this could be an option. Still, it will limit your configuration, and you might need this feature.

Smurf attack Transmission

The Smurf attack can start from a Trojan horse or malware. It can be downloaded by somebody on the network and executed, or it can be in the form of an application. It is important to educate your staff about the dangers of phishing attacks that can lead to such problems. 

The smurf will remain hidden, on the infected host, for a long time until the attack needs it. Then he or she will activate it, and the process of generation of ICMP packets with a spoofed IP address will start. They will be targeted at the victim, and the DDoS attack will start.

Impact of Smurf DDoS Attack

A successfully executed Smurf DDoS attack can cause severe and far-reaching damage. That is why it is important to be aware of the potential consequences.

• Service Disruption: The primary goal of a DDoS attack, including Smurf attacks, is to disrupt the availability of services. By flooding the victim’s network with traffic, legitimate users are unable to access essential services, leading to downtime and potential loss of revenue.
• Resource Exhaustion: Smurf attacks can overwhelm network infrastructure, including routers, switches, and servers, leading to resource exhaustion. As a result, the victims can experience degraded performance or even complete system failure.
• Reputation Damage: A prolonged DDoS attack can tarnish the reputation of an organization, corrupting trust among customers and partners. The perception of unreliability and insecurity can have long-lasting consequences for the victim’s brand.
• Financial Losses: The financial impact of a Smurf DDoS attack can be significant. That includes not only immediate costs associated with mitigating the attack but also long-term losses originating from decreased productivity and loss in customer trust.

What is Fraggle attack, and how does it differ from Smurf attack?

The Fraggle attack is very similar to the Smurf attack, as both are Distributed Denial of Service (DDoS) attacks that send massive numbers of echo requests with spoofed source IP addresses. However, the primary difference is that the Fraggle attack involves sending User Datagram Protocol (UDP) broadcast packets over ports 7 and 19, instead of the usual ICMP packets used in the Smurf attack. In other words, while the Smurf attack focuses on flooding the victim’s network with ICMP echo requests, the Fraggle attack spreads the attack traffic across a greater area of the target system.

The goal of both the Smurf and Fraggle attacks is the same — to send an overwhelming volume of data to the server or network, quickly overloading it and causing it to crash or become unusable. However, the Fraggle attack has the advantage of avoiding detection by traditional firewall configurations since UDP broadcast packets are usually allowed by most firewalls. It is also important to note that Fraggle attacks can be used in conjunction with Smurf attacks for an even more significant impact. in conjunction with Smurf attacks for an even greater impact.

Conclusion

Staying safe online is getting harder every day. But you and your business can still be protected. By learning about threats like the Smurf attack and other DDoS attacks, you can understand how to stay safe. Use DDoS protection, and don’t let bad actors negatively influence the work of your servers. 

The post What is a Smurf DDoS attack? appeared first on ClouDNS Blog.

What is User Datagram Protocol?

The short acronym UDP stands for User Datagram Protocol, and it is a communication protocol applied across the Internet. It sets low-latency and loss tolerating connections between the different applications.

UDP offers fast communication due to the fact it allows data transfer before the receiving party provides an agreement. Therefore, UDP is highly valuable in communications that require speed and are considered time-sensitive. For example, Voice over IP (VoIP), Domain Name System (DNS) lookup, and video or audio playback.

Yet, this protocol is prone to data packet loss during travel from the source to the target destination. As a result, it could create some difficulties with the data transfer and makes it easy for cybercriminals to execute a Distributed Denial-of-Service (DDoS) attack.

History of UDP

User Datagram Protocol (UDP) emerged in the 1980s as part of the TCP/IP suite. It was initially developed for the ARPANET project, also known as the precursor to today’s internet. Created by David P. Reed and others, UDP was designed for simplicity and efficiency in transmitting datagrams, making it ideal for applications where speed and low overhead are priorities.

Unlike TCP, UDP does not guarantee delivery or order of packets, nor does it manage connections. This lack of reliability allows UDP to be lightweight, making it suitable for real-time applications like video streaming, online gaming, and voice-over IP (VoIP).

User Datagram Protocol gained fame due to its use in early internet protocols and applications, including DNS (Domain Name System) and DHCP (Dynamic Host Configuration Protocol). Nowadays, it continues to be widely used in various networked applications where low latency and reduced overhead are critical.

Despite its simplicity, UDP’s lack of error correction and flow control means it’s vulnerable to packet loss and out-of-order delivery. However, its efficiency and speed make it necessary in many networking scenarios, complementing TCP’s reliability with a lightweight alternative for specific use cases.

How does it work?

UDP (User Datagram Protocol) acts in a simple way by transferring data between two devices in a network. It transmits packets (datagrams) straight to the target device without setting a connection, specifying the packets’ order, or examining if they are delivered as arranged. 

Compared to TCP (Transmission Control Protocol), UDP provides more speed, yet it is not so reliable. 

TCP communication involves a process known as a “handshake,” which establishes the connection. In addition, only when it is completed the transfer of data packets could happen.

On the other hand, the UDP connection is not including this “handshake” process which means one device simply starts sending the information to the receiving one. Additionally, UDP communications do not include details about the order or confirmation for the arrival of the data. It is exactly the opposite when it comes to TCP.

Based on these characteristics, UDP has the ability to transfer data packets a lot faster than TCP.

The downside of a UDP connection is the loss of packets during the transit, which is not going to be resent as they are in TCP connections. Therefore, when applications implement UDP, they should be able to tolerate losses, duplications, or errors.

TCP Monitoring vs. UDP Monitoring

UDP header

UDP (User Datagram Protocol) operates with headers. It uses them for packaging the message data to be sent over the network. Each UDP header includes several parameters, also known as fields, which are determined by the technical specifications of the protocol.

The UDP (User Datagram Protocol) header contains four main fields. Each of them is 2 bytes. The UDP header has the following fields:

• Source port – It is 16-bit data that specifies the precise port which is going to send the packet. In case the target device doesn’t need to reply to the sender, this field could be set to zero.
• Destination port – It is 16-bit data that serves to specify application-level service on the target device, meaning the port of the device receiving the data. It could be between 0 and 65,535.
• Length – It defines the entire number of bytes, including the UDP header and the UDP data packets for transfer. The precise limit for the UDP length field is defined with the underlying IP protocol utilized to send the data.
• Checksum – It is a 16-bits field, an optional field. The checksum gives the ability for the receiving device to confirm the integrity of the packet header and payload. It is an optional field, meaning if the application wants the checksum or not. In case it doesn’t want the checksum, then all of the 16 bits are zero. In UDP, the checksum field is used for the header and data part. In IP, the checksum field is used only for the header field. It is optional in IPv4, yet it is required in IPv6.

Applications relying on UDP

Gaming, voice, and video

The User Datagram Protocol is a great choice for various different network applications that require minimum latency, like gaming, voice, and also video communications. Services like these will not lower their quality if some of the data packets are lost during the transfer. Yet, despite the lost packets, there is a chance to implement techniques for further error correction and improvement of the audio and video quality. 

Domain Name System Lookups

DNS queries are small and simple requests which receive basic and straightforward answers. A device initiates a DNS query to the DNS servers for receiving essential information about a domain, like the IP address (IPv4 or IPv6). The process is on hold until the DNS query receives its reply. Due to the fact that TCP uses a three-way handshake procedure, it means the request is probably going to be answered very slowly. As a result, it will affect the performance in a negative way. For that reason, DNS queries rely on UDP for quick answers.

Why does DNS use UDP?

Multicasting

Another way for implementing UDP (User Datagram Protocol) is for multicasting. That is based on the fact it supports packet switching. Moreover, this network protocol could also be implemented for additional routing update protocols, for instance, Routing Information Protocol (RIP).

UDP vs. TCP – what are the differences?

Let’s explain a little bit more about what are the main differences between these two protocols:

• Type of protocol

Both TCP and UDP are transport layer protocols. However, there is a main contrast between them. TCP is a connection-oriented protocol. On the other side, UDP is a connectionless protocol. So, simply TCP needs to establish the connection before the communication, while UDP does not need to ensure that the two devices have a connection.

• Reliability

TCP is considered a reliable protocol based on the fact it ensures the delivery of the data packets. It involves an acknowledgment mechanism, in which the sender gets the acknowledgment from the receiver and examines if it is positive or negative. In case it is positive, the data has been delivered successfully. If it is negative, TCP is going to resend the data.

UDP is considered an unreliable protocol based on the fact it does not provide any guarantee that the delivery of the data has been successful.

• Flow Control

TCP involves a flow control mechanism. It makes sure that an extensive number of packets are not sent to the target device simultaneously. On the other hand, UDP does not implement this flow control mechanism at all.

• Ordering

TCP operates with ordering and sequencing techniques. That way, it guarantees that the data packets are going to be delivered in the absolutely exact order in which they were sent. On the other side, UDP does not involve any ordering and sequencing techniques. That means the data could be transferred in any order.

• Speed

As we mentioned, the first step for TCP is to build the connection between the two devices. Additionally, it completes a check for errors and makes sure that the transmission of the data packets is successful. On the other hand, UDP does not build a connection or ensure the transmission. For that reason, UDP is way faster than TCP.

• Flow of data

When we speak about TCP, it offers the full-duplex service. That means the information is able to flow in both directions. Additionally, when we take a look at UDP, it is more fitting for the unidirectional flow of data.

Is UDP secure?

UDP (User Datagram Protocol) serves a great purpose for applications that tolerate packet loss. That is not an issue. Yet, based on the fact that UDP is a connectionless protocol and it does not implement a “handshake” procedure provides an opportunity for cybercriminals. They take advantage of that by flooding their victim with UDP traffic. Attackers do not need to establish a connection and receive permission for initiating such a DDoS attack.

Usually, the UDP flood attack involves sending a massive amount of UDP datagrams to different ports on the victim’s device. That causes the victim to answer with the same amount of ICMP packets indicating that these ports are unreachable. As a result, the victim’s resources are exhausted, and the DDoS attack is completed.

What is flood attack?

Thankfully there are different ways to protect your device, network, server from such malicious attempts. 

• You can limit the response rate of ICMP packets. However, you should know that this could filter out legitimate packets too.

Suggested page: Explanation of ICMP Ping traffic monitoring

• A robust network of many servers (such as Anycast DNS) is a great way to prevent a single server from being drowned with malicious requests.
• Especially for your DNS network, it is a great approach to implement DDoS protection.

Advantages and Disadvantages of UDP

By understanding the main advantages and disadvantages of User Datagram Protocol, you can determine if it is the right protocol for your application. So, let’s take a closer look at what this interesting protocol can offer. 

Advantages of UDP

The User Datagram Protocol provides several benefits, which are the following:

• Fast: It does not require the establishment of a connection before transmitting data, which makes it faster than TCP.’
  Suggested page: Explanation of TCP monitoring
• More efficient: UDP is a lightweight protocol that requires less overhead than TCP.
• Suitable for real-time applications: User Datagram Protocol is ideal for real-time applications, such as online gaming, video conferencing, and live streaming, where speed is more important than reliability.

Disadvantages of UDP

The main drawbacks of the User Datagram Protocol include the following:

• No reliability: It does not guarantee the delivery of packets or guarantee that packets will arrive in order.
• No congestion control: UDP does not have congestion control mechanisms, which means that it can flood a network with packets if not used carefully.
• Limited use cases: User Datagram Protocol is not suitable for applications that require reliable data transmissions, such as file transfers, email, or web browsing.

Suggestes article: Secure File Transfer Protocol (SFTP) Explained

UDP monitoring from ClouDNS – What is it and how to use it?

UDP monitoring is a type of network monitoring that involves scanning a selected UDP port number on a given IP address to check the availability of a service or application. Suppose the monitoring system is unable to establish a connection with the selected port. In that case, it marks the check as DOWN, indicating that the service is unavailable or experiencing issues. UDP monitoring is extremely helpful for identifying potential network problems or service disruptions before they affect end users. In addition, it allows network administrators to quickly diagnose and resolve issues, ensuring that critical services are available and performing optimally.

Conclusion

For sure, the development of UDP (User Datagram Protocol) is revolutionary. It allows fast delivery, which is highly valuable for a number of applications. UDP finds its purpose in many services despite the fact it has some downsides, mainly in DNS, video streaming, and gaming.

The post UDP (User Datagram Protocol) explained in details appeared first on ClouDNS Blog.