Router

A router is one of the network devices that handles network traffic. It does it by forwarding data packets between different computer networks. When the router receives the data packets, it will check it, and it will compare it with its routing table. Then it will decide to send it to the next network toward the destination of the packets or not. Most of you are probably familiar with the routers. You probably have one at home, which manages packets from the home computer to the internet.

Functionalities of routers 

• IP address management: Routers assign IP addresses to devices within a network and provide network address translation (NAT) functionality to map multiple private IP addresses to a single public IP address.
• Traffic management: Routers implement Quality of Service (QoS) mechanisms to prioritize and manage network traffic based on predefined rules.
• Network segmentation: Routers allow for the creation of separate network segments, known as subnets, to enhance security and optimize network performance.

Firewall

Firewall, as the name suggests, is a barrier. Its purpose is to protect the devices behind it by filtering the data from coming to them and going from them and protecting from harmful communications like spam or viruses. It can be hardware, with router capability or just software, like the one Windows has.

Key features of firewalls

• Packet filtering: Firewalls examine packets based on predefined rules, such as source/destination IP addresses, ports, and protocols, to determine whether they should be allowed or blocked.
• Stateful inspection: Firewalls maintain state information about established connections, allowing them to make intelligent decisions regarding packet filtering and preventing unauthorized access.
• Application-level filtering: Some firewalls can perform deep packet inspection to analyze the content of packets at the application layer (Layer 7), enabling them to detect and block specific application-layer threats.

Importance of Firewall Monitoring

Firewall monitoring is a critical aspect of network security management. It involves continuous monitoring, analysis, and maintenance of firewall rules and logs to ensure optimal firewall performance and detect potential security incidents. Effective Dynamic Host Configuration Protocol provides the following 4 benefits:

1. Threat detection and prevention: By monitoring firewall logs and analyzing network traffic patterns, administrators can identify suspicious activities, such as unauthorized access attempts, malware infections, or data exfiltration, and take proactive measures to mitigate them.
2. Policy compliance: Firewall monitoring helps ensure that security policies and rules are consistently enforced, reducing the risk of policy violations and non-compliance with industry regulations.
3. Performance optimization: Regular monitoring enables administrators to identify and resolve performance bottlenecks, fine-tune firewall configurations, and optimize network traffic flow, thus enhancing overall network performance.
4. Incident response: In the event of a security incident, firewall logs provide crucial information for forensic analysis and incident response. Monitoring allows for the timely detection and response to security breaches, minimizing potential damage.

Router vs firewall

To easily understand the router vs firewall topic, see this table:

Hardware firewall vs software firewall

Now to a bit of a different subject, hardware firewall vs software firewall. Both protect you from malicious traffic, but they have some differences.

The hardware firewall can be a stand-alone device or a part of a router. Such a router is a simple and effective protection solution for your network. It reviews the headers of the data packets and decides if it can be trusted. If it thinks the packet is safe, it will forward it, if no, it will drop it.

A software firewall is a program that you can install on your computer. It can be a part of an antivirus suite or separate. It will protect from uncontrolled access to your computer. Depending on the software, it can keep you safe from Trojans and worms too. The difference with the hardware one, this one will protect just the device that has the firewall installed. If you need a firewall on all of your devices, you would need to install it on all of them. Another disadvantage of it is that it will run in the background, which will take some system resources and may lead to slowdowns.

How do DHCP, routers, and firewalls work together?

DHCP, which stands for Dynamic Host Configuration Protocol, is responsible for assigning IP addresses to devices within a network. It acts as a mediator between routers and firewalls, ensuring that devices can communicate with each other and stay secure.

Routers are like traffic directors. They help direct data packets between different networks, ensuring they reach their intended destinations. Some routers also have built-in DHCP server functionality, allowing them to assign IP addresses to devices in the network.

Firewalls, on the other hand, are like security guards. They monitor and control the flow of network traffic to protect against unauthorized access and potential threats. While firewalls primarily focus on security, they can interact with DHCP in a couple of ways.

Firstly, firewalls can act as DHCP relays. If devices and DHCP servers are on different network segments, the firewall helps relay the DHCP messages between them, ensuring that devices can still get their assigned IP addresses.

Secondly, firewalls can inspect DHCP traffic and apply rules to allow or block it. This filtering capability helps prevent unauthorized DHCP servers or DHCP attacks from compromising the network’s security.

Lastly, firewalls can use DHCP lease information to enforce security policies. By looking at the DHCP lease table, they can identify devices based on their assigned IP addresses and apply specific security rules or identify potential unauthorized devices on the network.

In simpler terms, DHCP ensures devices have IP addresses to communicate, routers direct the traffic, and firewalls protect the network by working alongside DHCP to manage IP addresses and filter network traffic.

Switches vs routers vs firewalls: How do they fit together?

In a typical network setup, devices such as computers and printers connect to a switch. The switch facilitates internal communication within the local network by forwarding data packets based on MAC addresses.

The switch then connects to a router. The router manages traffic between different networks by using IP addresses to route data packets. It ensures that data from your local network reaches its destination on other networks, such as the internet.

Finally, the router connects to a firewall. The firewall acts as a barrier, inspecting and filtering traffic to protect your network from unauthorized access and cyber threats. By examining data packets based on security rules, the firewall ensures that only safe and authorized traffic enters or leaves the network.

Example Setup:

Devices -> Switch -> Router -> Firewall -> Internet

This configuration ensures that devices can communicate within the local network, that traffic is efficiently managed and routed to appropriate destinations, and that the network is protected from external threats. This collaborative setup of switches, routers, and firewalls provides a robust, efficient, and secure network infrastructure.

Conclusion

Routers and firewalls play vital roles in securing networks and protecting sensitive information. While routers focus on efficiently forwarding data packets between networks, firewalls provide an additional layer of security by monitoring and controlling network traffic based on predefined rules. Both are essential components of a robust network security architecture.

The post Router vs firewall, can you guess which is better? appeared first on ClouDNS Blog.

In today’s article, we will dive into the significance of Firewall Monitors, specialized tools that go beyond traditional firewall functions. They not only provide real-time monitoring, logging, and reporting capabilities but also act as proactive defenders against evolving cyber threats. In this brief overview, we’ll explore the importance, operational mechanisms, and benefits of Firewall Monitors, essential components in fortifying network security in today’s dynamic environment.

Understanding Firewalls

Before we explore the meaning and significance of Firewall Monitor, it is essential to understand the basic concept of firewalls. A firewall is a network security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. The primary goal of a firewall is to establish a barrier between a trusted internal network and untrusted external networks, such as the Internet.

Firewalls can operate at different layers of the OSI (Open Systems Interconnection) model, including the network layer and the application layer. Additionally, they can be implemented as hardware appliances, software applications, or a combination of both. Firewalls use a set of rules to determine whether to allow or block traffic, and these rules are typically configured by network administrators based on the organization’s security policies.

What is a Firewall Monitor?

A Firewall monitor is a specialized tool or application designed to enhance network security and analyze network traffic passing through a firewall. They offer real-time monitoring, logging, and reporting capabilities, allowing organizations to gain insights into traffic patterns, identify potential threats, and respond proactively to security incidents.

While firewalls are instrumental in preventing unauthorized access and protecting network resources, they are not always effective. Cyber threats are constantly evolving, and attackers constantly try new advanced techniques to bypass traditional security measures. That is why Firewall monitor come into play, providing an additional layer of defense and improving the overall security.

Discover Firewall Monitoring service by ClouDNS

Why is it Important?

The importance of a Firewall Monitor is significant in the context of modern cybersecurity challenges. As cyber threats become even more advanced, traditional firewall solutions may fall short of providing adequate protection. A Firewall Monitor addresses this gap by offering a proactive and dynamic approach to network security.

One of the key reasons for its importance lies in its ability to detect and respond to emerging threats in real time. By closely monitoring network traffic, a Firewall Monitor can identify unusual patterns or behaviors that may indicate a potential security threat. This timely detection allows administrators to take swift action, mitigating the impact of the attack before it can cause significant harm to the network.

Moreover, such a tool plays a crucial role in compliance management. Many industries and organizations are subject to strict regulatory requirements regarding data protection and privacy. By maintaining detailed logs of network activity, a Firewall Monitor helps in demonstrating compliance with these regulations, reducing the risk of legal consequences and financial penalties.

How Does the Firewall Monitor Work?

The functionality of a Firewall Monitor circles around continuous monitoring, analysis, and reporting of network traffic. Here’s a brief overview of how it works:

1. Continuous Monitoring: A Firewall Monitor constantly observes incoming and outgoing data packets, keeping a watchful eye on the entire network. It examines the source and destination of each packet, the type of data being transmitted, and the specific applications or services involved.
2. Anomaly Detection: Using advanced algorithms and predefined security rules, it identifies anomalies or deviations from normal traffic patterns. For example, it could catch sudden spikes in data volume, suspicious communication patterns, or attempts to access restricted areas of the network.
3. Logging and Reporting: Once anomalies are detected, the Firewall Monitor generates detailed logs and reports. These logs provide administrators with valuable information about the nature of the threat, the affected systems, and the potential impact on the network. With such comprehensive reporting, administrators can make informed decisions and proactively respond to security incidents.
4. Incident Response: In the event of a security incident, a Firewall Monitor can trigger automated responses or alerts to notify administrators. This can include blocking specific IP addresses, restricting access to certain resources, or activating additional security measures to contain the threat.

Benefits of Firewall Monitors

Some of the main advantages of implementing this advanced tool are the following:

• Enhanced Threat Detection: Firewall Monitors significantly improve threat detection capabilities by providing a comprehensive view of network activities. The combination of real-time monitoring, logging, and traffic analysis allows organizations to identify and respond to security threats promptly.
• Incident Response: In the event of a security threat, these tools play a crucial role in incident response. Detailed logs and reports help security teams trace the root cause of the incident, understand the extent of the compromise, and implement corrective measures to prevent future occurrences.
• Compliance and Reporting: Many industries and regulatory bodies require organizations to stick to specific security standards and compliance frameworks. Tools for monitoring and analysis are helpful in meeting these requirements by providing detailed reports and logs that demonstrate compliance with security policies and regulations.
• Network Optimization: Firewall monitors offer insights into network traffic patterns, helping organizations optimize their network infrastructure. By understanding the types of traffic and the volume of data flowing through the network, administrators can make informed decisions to improve performance and allocate resources more efficiently.
• Proactive Security Measures: With the ability to identify and respond to potential threats in real time, Firewall monitor enables organizations to adopt a proactive approach to cybersecurity. By staying ahead of emerging threats, organizations can minimize the likelihood of successful cyberattacks and protect sensitive information.

Conclusion

In summary, Firewall Monitor plays a crucial role in strengthening network security by providing real-time monitoring, anomaly detection, and incident response capabilities. As cyber threats evolve, these monitors offer a proactive defense, swiftly identifying and mitigating potential risks. Their contribution extends to compliance management, aiding organizations in meeting regulatory requirements through detailed logs and comprehensive reporting. With the ability to optimize network performance and respond to emerging threats, Firewall Monitor appears as an essential component in safeguarding networks from the dynamic landscape of cybersecurity.

The post Firewall Monitor Explained: Enhancing Network Protection appeared first on ClouDNS Blog.

Teardrop attack explained

The Teardrop attack or TCP fragmentation attack is a type of Denial-of-Service attack (DoS attack) that has the main goal to make a network, server, or computer inaccessible by sending them large amounts of altered data packets. 

Computer systems that are a bit older have a bug within the code used for handling large amounts of data. That weak spot is the perfect opportunity for initiating the Teardrop attack. Usually, the system should collect all bits and put them in the proper order. Yet, that never happens, and the system continues to wait for pieces that never arrive. As a result, the network, server, or device crashes.

You have probably guessed that the main targets of such DoS attacks are exactly the TCP/IP fragmentation codes. They are performed via a methodology that includes overlapping the fragmented packets of the device, server, or network. When the host tries to reconstruct the packets to their correct order, it typically fails, and eventually, the system crashes permanently. Moreover, the conditions get even worse because of the large amounts of load that are sent to the targeted device. Furthermore, as this malicious threat uses TCP/IP fragments, it’s also a part of the IP fragmentation attack.

The cybercriminals that are completing the attack are more commonly choosing the old versions of operating systems (OS). So, let’s say, for instance, older versions of Windows like Windows NT, Windows 3.1x, Windows 95, Windows 7, Windows Vista. Additionally, other targets could be Linux versions former to 2.0.32 and 2.1.63. Due to their sluggish processing speed and flawed TCP/IP fragments, these systems are unable to aggregate tainted packets.

You are probably assuming that such type of threat is a little bit outdated based on the fact that the new operating systems are not the main targets. However, it would be best if you did not underestimate the potential damage the Teardrop attack could cause. Just think about how many counties, large government, and healthcare organizations are using exactly a lot older versions of operating systems. 

What inspired the name of the attack?

Let’s now look at how it got its name, ‘Teardrop attack.’ The attack’s glitchy code is relatively tiny and fragmented. It is entered slowly and is only a small portion of a large part. This resembles a teardrop in practically every way. It just makes up a small portion of all the tears that a person can shed throughout their lifetime. When it comes to solo, a teardrop won’t have any impact. But when it’s plentiful, it can lead to a breakdown in emotions.

How does it work?

The majority of the systems are created in a simple way that does not allow the transfer of massive amounts of information from a different source in just one attempt. For that reason, systems manage to divide the data into fragments and transfer it like that. Then, relying on the rules established in the software, the recipient reassembles it. For specifying how much information they can process at a time, networks set maximum transmission units (MTUs). In the most common scenarios, a network uses a 1,500-byte limit. However, if you send something more extensive than that, then the following is going to happen:

• Fragmented – The device that wants to send the information, or the router that is related to it, divides the data into pieces – fragment datagrams.
• Sent – Each piece is transferred to the target destination containing headers that have the purpose of defining the precise order for reassembly.
• Reassembled – The server that is set as a target destination remains until the entire collection of fragments arrives. Once each of them is available, the system arranges the information in the proper order and delivers it. 

As we mentioned, operating systems (OS) that are a bit aged include a bug. That causes confusion through the phase of reassembly, which makes it possible to use that vulnerability.

Here is how the Teardrop attack is performed, step by step:

• First, the extensive amount of information is divided into small fragments before sending it across the Internet.
• Every piece gets a precise number which defines in which order the fragments should be arranged and assembled to receive the original information.
• The destination server uses the included information in the fragments to organize them in the right sequence.
• In this step, the Teardrop attack interferes and disrupts the fragments’ offset field. That makes it difficult for the device to reassemble the pieces.
• Then a lot of fraudulent packets are delivered on the device or server of the victim. So, finally, that causes the crash of the device.

The good news is that most of the current networks and devices are able to efficiently notice damaged fragmented packets because of their development. If a discrepant packet is recognized, it is possible to restrict it and prevent a Teardrop attack.

What are the effects of the Teardrop DoS attack?

Based on the fact that the Teardrop DoS attack is initiated and targets the TCP/IP reassembly mechanisms and disturbs them from setting together fragmented packets of data. That leads to the overlapping of data packets and overwhelming servers of the victim, which causes them to go down.

Whenever the Teardrop DoS attack is completed, the system, server, or network gets confused. Additionally, it pauses for some time and then crashes. As an effect of it, when the server is down, it is not capable of providing the needed resources, and for instance, your employees won’t be able to do their work at all.

Who are the likely victims of this attack type?

There are some organizations that are more likely to be a target of a Teardrop attack. Typically they are a bit more traditional and are hardly willing to implement the new technologies. It is also common for them to have the understanding that new technologies could affect their operations. Therefore they use a bit older technologies and software. Here are some of the common targets and likely victims of the Teardrop attack:

• Healthcare

More than half of healthcare providers are using some of the old versions of operating systems (OS). In the most popular scenarios, it is exactly Windows 7. That is the reason why they are especially vulnerable to these attacks. Mainly because Microsoft announced that it is not going to continue to support that version of their product.

• Government

Other institutions that are using pretty old systems and technology are precisely the ones related to government. There are cases in which the Office of Personnel Management (OPM) was attacked, and all of the information was not encrypted. Why? Because the system was way too old. Systems like that are very likely to become victims of the Teardrop attack.

• Banking, Financial Services, and Insurance (BFSI)

In the past years, we have seen a massive improvement and change in the different financial services, and probably all of them implemented the usage of mobile apps. However, if we take a look at what they are implementing to their backend systems, we are going to notice that in most cases, their technologies are not actually brand new. They prefer to operate with legacy systems, but that makes them very vulnerable to Teardrop attacks.

How to protect ourselves?

• Update the version of your OS.

With just this simple task, you are making sure that your device is hard to become a target to such a DoS attack. It is essential not to use an aged OS that is not supported anymore, and there aren’t any security patches. In case you are using such an operating system, you won’t receive updates anymore. That makes you prone to experience not only a Teardrop attack but also some DDoS attack types. (If you are searching for a reliable DNS protection, check our DDoS Protected DNS Service)

• Monitor your systems

You can add an extra layer of security to your system through a Monitoring service. It includes different types of checks. Especially TCP monitoring and Heartbeat мonitoring in a Teardrop attack situation will help a lot. It is a technique for keeping a close eye on a system’s health by regularly sending heartbeat events to a remote monitoring service. For example, if the data included in the heartbeat event does not match the user-defined assertions, it will be notified that something is wrong. So, this would be a clear signal for a defense action.

• Firewall

These attacks target the network layer, so your system should certainly be protected. You can implement a reliable firewall system that filters unwanted data. There are a lot of different types of firewalls. For sure, one of them is going to fit your network’s requirements. It is crucial to enable an efficient filter that is going to help you detect and stop infected data. It serves as an excellent protection method.

How to detect it?

Detecting the presence of a Teardrop Attack can be challenging, considering its ability to camouflage within the network’s regular traffic. However, there are several signs and symptoms that administrators and security personnel can observe:

• System Instability: One of the primary indicators of a Teardrop Attack is the sudden instability or unresponsiveness of systems and network devices. Sluggish response times, increased latency, and interrupted connectivity can indicate that your system is under attack. Users might experience frequent crashes, freezes, or abnormal behavior in applications and services.
• Unusual Network Activity: Strange network behavior, such as an unexpected surge in network traffic or a sudden increase in packet fragmentation, could be a red flag indicating a potential Teardrop Attack. Monitoring network traffic for irregular patterns becomes crucial in detecting such anomalies.
• System Logs and Error Messages: Regularly reviewing system logs and error messages can reveal clues about attempted attacks or system anomalies caused by a Teardrop Attack. Unusual error messages related to packet handling or IP reassembly could hint at malicious activities.

Why are Teardrop attacks so important?

A great number of people are still using systems that are considered very old. Additionally, the companies that provided these tools are not supporting them anymore. For instance, there are still organizations that hold a device that operates with Windows XP. Yet, the support ended back in 2014. There are various cyber threats, and the Teardrop attack is one of them that proves how important it is to update your systems.

In case you are using software that is modern and you update it on time, it is going to be a lot harder for an attacker to initiate a Teardrop attack towards you or your business. The reason for that is simple. The vulnerability that is required for performing the attack just doesn’t exist, and attackers can’t take advantage of it. Therefore it is essential to know the way IP fragmentation attacks such as Teardrop are made.

Conclusion

So, now you understand actually how dangerous a Teardrop attack is. It could affect your device, network or computer. For that reason, it is extremely important to keep yourself and your network safe and take the required actions to prevent it.

The post What is a Teardrop attack, and how to protect ourselves? appeared first on ClouDNS Blog.