security

Implementing Network Security

Implementing Network Security

In today's interconnected world, where technology reigns supreme, the need for robust network security measures has become paramount. This blog post aims to provide a detailed and engaging guide to implementing network security. By following these steps and best practices, individuals and organizations can fortify their digital infrastructure against potential threats and protect sensitive information.

Network security is the practice of protecting networks and their infrastructure from unauthorized access, misuse, or disruption. It encompasses various technologies, policies, and practices aimed at ensuring the confidentiality, integrity, and availability of data. By employing robust network security measures, organizations can safeguard their digital assets against cyber threats.

Before diving into the implementation process, assessing the vulnerabilities within your network is crucial. Conduct a comprehensive audit to identify potential weak points, such as outdated software, unsecured access points, or inadequate user authentication protocols. This initial step lays the foundation for tailored security measures.

Table of Contents

Highlights: Implementing Network Security

Network Visibility

Appropriate network visibility is critical to understanding network performance and implementing network security components. Much of the technology used in network performance, such as Netflow, is security-focused. There is a challenging landscape; workloads move to the cloud without monitoring or any security plan. We need to find a solution to have visibility over these clouds and on-premise applications without refuting the entire tracking and security stack.

Networking is Complex

Our challenge is that the network is complex and constantly changing. We have seen this with WAN monitoring and the issues that can arise from routing convergence. This may not come as a hardware refresh, but it constantly changes from a network software perspective and needs to remain dynamic. If you don’t have complete visibility while the network changes, this will result in different security blind spots.

Security Tools

Existing security tools are in place, but better security needs to be integrated. And here, we can look for the network and provide that additional integration point. In this case, we can use a network packet broker for sitting in the middle and feeding all the security tools with data that has already been transformed or, let’s say, optimized for that particular security device it is sending back to, reducing false positives.

Related: For pre-information, you may find the following post helpful:

  1. Technology Insight For Microsegmentation
  2. SASE Visibility
  3. Network Traffic Engineering
  4. Docker Default Networking 101
  5. Distributed Firewalls
  6. Virtual Firewalls



Implementing Network Security.

Key Implementing Network Security Discussion points:


  • The use of a network packet broker.

  • Monitoring and Observability.

  • The different hacking stages.

  • How to implement network security.

  • The issues with encrypted traffic.

Back to Basics: Implementing Network Security

The Role of Network Security

For sufficient network security to be in place, it is essential to comprehend its central concepts and the implied technologies and processes around it that make it robust and resilient to cyber-attacks. However, all of this is complicated when the visibility is blurred by not having a demarcation of the various network boundaries.

Moreover, network security touches upon multiple attributes of security controls that we need to consider, such as security gateways, SSL inspection, threat prevention engines, policy enforcement, cloud security solutions, threat detection and insights, and attack analysis w.r.t frameworks, to name a few.

implementing network security
Diagram: Implementing network security.

One of the fundamental components of network security is the implementation of firewalls and intrusion detection systems (IDS). Firewalls act as a barrier between your internal network and external threats, filtering out malicious traffic. On the other hand, IDS monitors network activity and alerts administrators of suspicious behavior, enabling rapid response to potential breaches.

Enforcing Strong Authentication and Access Controls

Unauthorized access to sensitive data can have severe consequences. Implementing robust authentication mechanisms, such as two-factor authentication (2FA) or biometric verification, adds an extra layer of security. Additionally, enforcing stringent access controls, limiting user privileges, and regularly reviewing user permissions minimize the risk of unauthorized access.

Regular Software Updates and Patch Management

Cybercriminals often exploit vulnerabilities in outdated software. Regularly updating and patching your network’s software, including operating systems, applications, and security tools, is crucial to prevent potential breaches. Automating the update process helps ensure your network remains protected against emerging threats whenever possible.

Data Encryption and Secure Communication

Protecting sensitive data in transit is essential to maintain network security. Implementing encryption protocols, such as Secure Sockets Layer (SSL) or Transport Layer Security (TLS), safeguards data as it travels across networks. Additionally, using Virtual Private Networks (VPNs) ensures secure communication between remote locations and adds an extra layer of encryption.

Site to Site VPN

Assessing Vulnerabilities

Conducting a comprehensive assessment of your network infrastructure before diving into network security implementation is crucial. Identify potential vulnerabilities, weak points, and areas that require immediate attention. This assessment will serve as a foundation for developing a tailored security plan.

Building a Strong Firewall

One of the fundamental elements of network security is a robust firewall. A firewall acts as a barrier between your internal network and the external world, filtering incoming and outgoing traffic based on predefined rules. Ensure you invest in a reliable firewall solution with advanced features such as intrusion detection and prevention systems.

Firewall traffic flow
Diagram: Firewall traffic flow and NAT

Enforcing Access Controls

Controlling user access is vital to prevent unauthorized entry and data breaches. Implement strict access controls, including strong password policies, multi-factor authentication, and role-based access controls (RBAC). Regularly review user privileges to ensure they align with the principle of least privilege (PoLP).

Encrypting Data

Data encryption is critical to network security, mainly when transmitting sensitive information. Utilize industry-standard encryption algorithms to protect data at rest and in transit. Implement secure protocols like HTTPS for web communication and VPNs for remote access.

Monitoring and Intrusion Detection

Network security is an ongoing process that requires constant vigilance. Implement a robust monitoring and intrusion detection system (IDS) to detect and respond promptly to potential security incidents. Monitor network traffic, analyze logs, and employ intrusion prevention systems (IPS) to protect against attacks proactively.

Monitoring Observability

Increased enterprise security challenges demand new efforts and methods to stay ahead of threat actors. Therefore, monitoring the environment must be taken from multiple vantage points. Then, we can identify patterns that could be early indicators of attack. Finally, once we know there is an attack, we can implement a proactive response model, which will be crucial to success. 

We need good network observability tools to understand what is happening in your environment. Bad actors are always at work, going through new things and creating new ways to exploit. Consider how you gain complete network visibility when deciding on your monitoring solution. We must assume that the actor already has access to the zero-trust approach to security.

So we assume the threat already has access and authentication at all levels, along with having the correct security appliance in places such as the Web Application Firewalls (WAF), Intrusion Detection Systems (IDS), and Intrusion Prevention System (IPS). But the most crucial point is to assume we have a breach and the bad actor is already on our network.

Hacking Stages

♦ The hacking stages

There are different stages of an attack chain, and with the correct network visibility, you can break the attack at each stage. Firstly, there will be the initial recon, access discovery, where a bad actor wants to understand the lay of the land to determine the next moves. Once they know this, they can try to exploit it. 

network derived intelligence
Diagram: Network-derived intelligence.
    • Stage 1: Deter

You must first deter threats and unauthorized access, detect suspicious behavior and access, and automatically respond and alert. So, it would help if you looked at network security. We have our anti-malware devices, perimeter security devices, identity access, firewalls, and load balancers for the first stage, which deters.

    • Stage 2: Detect

The following dimension of security is detection. Here, we can examine the IDS, log insights, and security feeds aligned with analyses and flow consumption. Again, any signature-based detection can assist you here.

    • Stage 3: Respond

Then, we need to focus on how you can respond. This will be with anomaly detection and response solutions. Remember that all of this must be integrated with, for example, the firewall enabling you to block and then deter that access.

  • A key point: Red Hat Ansible Tower  

Ansible is the common automation language for everyone across your organization. Specifically, Ansible Tower can be the common language between security tools. This leads to repetitive work and the ability to respond to security events in a standardized way. If you want a unified approach, automation can help you here, especially with a Platform such as Ansible Tower. It would help if you integrated Ansible Tower and your security technologies. 

Example: Automating firewall rules. We can add an allowlist entry in the firewall configuration to allow traffic from a particular machine to another. We can have a playbook that first adds the source and destination I.P.s as variables. Then, when a source and destination object are defined, the actual access rule between those is defined. All can be done with automation.

Ansible vs Tower
Diagram: Ansible vs Tower. Source Red Hat.

Implementing Network Security

There is not one single device that can stop an attack. We need to examine multiple approaches that should be able to break the attack at any part of this attack chain. Whether the bad actors are doing their TCP scans, ARP Scans, or Malware scans. You want to be able to identify these before they become a threat. You must always assume threat access, leverage all possible features, and ensure every application is critical and protected. 

We must improve various technologies’ monitoring, investigation capabilities, and detection. This is where the zero-trust architecture can help you monitor and improve detection. In addition, we must look at network visibility, logging, and Encrypted Traffic Analyses (ETA) to improve investigation capabilities.

Network-derived intelligence

So, when implementing network security, you need to consider that the network and the information gleaned from it add a lot of value. This can still be done with an agent-based approach, where an agent collects data from the host and sends it back to, for example, a data lake where you set up a dashboard and query. However, an agent-based approach will have blind spots. It misses a holistic network view and can’t be used with unmanaged devices like far-reaching edge IoT.

The information gleaned from the host misses out on data that can be derived for the network. Especially with network-derived traffic analysis, you can look into unmanaged hosts such as IoT: any host and its actual data.

This is not something that can be derived from a log file. The issue we have with log data is if a bad actor gets internal to the network, the first thing they want to do to cover their footprints is log spoofing and log injections.

Agent-based and network-derived intelligence

An agent-based approach and network-derived intelligence’s deep packet inspection process can be appended. Network-derived intelligence allows you to pull out tons of metadata attributes, such as what traffic this is, what the characteristics of the traffic are, what a video is, and what the frame rate is.

The beauty is that this can get both north-south and east-west traffic and unmanaged devices. So, we have expanded the entire infrastructure by combining an agent-based approach and a network-derived intelligence.

Detecting rogue activity: Layers of security 

Now, we can detect new vulnerabilities, such as old SSL ciphers, shadow I.T. activity, such as torrent and crypto mining, and suspicious activities, such as port spoofing. Rogue activities such as crypto mining are a big concern. Many workflows get broken, and many breaches and attacks install crypto mining software.

This is the best way for a bad actor to make money. The way to detect this is not to have an agent but to examine network traffic and look for anomalies in the traffic. When there are anomalies in the traffic, the traffic may not look too different. This is because the mining software will not generate log files, and there is no command and control communication. 

We make the observability and SIEM more targeted to get better information. With the network, we have new capabilities to detect and invent. This adds a new layer of defense in depth and makes you more involved in the cloud threats that are happening at the moment. Netflow is used for network monitoring, detection, and response. Here, you can detect the threats and integrate them with other tools so we can see the network intrusion as it begins. It makes a decision based on the network. So you can see the threats as they happen.

layers of security
Diagram: Layers of security.

Security Principles: Monitoring and Observability

So, when implementing network security, we must follow security principles and best practices. Firstly, monitoring and observability. To set up adequate security controls on a zero-trust network, you need to have a clear picture of all the users and devices with access to a network and what access privileges they require to do their jobs.

Therefore, the comprehensive audit you must take should include up-to-date access lists and policies. We also need to ensure that network security policies are kept up to date. Testing their effectiveness regularly is an excellent idea to ensure that no vulnerabilities have escaped notice. Finally, monitoring. Zero-trust network traffic is constantly monitored for unusual or suspicious behavior.

You can’t protect what you can’t see.

The first step in the policy optimization process is how the network connects, what is connecting, and what it should be. You can’t protect what you can’t see. Therefore, everything desperately managed within a hybrid network must be fully understood and consolidated. Secondly, once you know how things connect, how do you ensure they don’t reconnect through a broader definition of connectivity?

zero trust environment

You must support different user groups, security groups, and IP addresses. You can’t just rely on IP addresses to implement security controls anymore. We need visibility at traffic flow, process, and contextual data levels. Without this granular application, visibility, mapping, and understanding normal traffic flow and irregular communication patterns is challenging.

Complete network visibility

We also need to identify when there is a threat easily. For this, we need a multi-dimensional security model and good visibility. Network visibility is integral to security, compliance, troubleshooting, and capacity planning. Unfortunately, custom monitoring solutions cannot cope with the explosive growth networks.

We also have reasonable solutions from Cisco, such as Cisco’s Nexus Dashboard Data Broker (NDDB).  Cisco’s Nexus Dashboard Data Broker (NDDB) is a packet brokering solution that provides a software-defined, programmable solution that can aggregate, filter, and replicate network traffic using SPAN or optical TAPs for network monitoring and visibility. 

What prevents visibility?

There is a long list of things that can prevent visibility. Firstly, there are too many devices and complexity and variance between vendors in managing them. Even CLI commands from the same vendor vary. Too many changes result in the inability to meet the service level agreement (SLA), as you are just layering on connectivity without fully understanding how the network connects.

This results in complex firewall policies. For example, you have access but are not sure if you should have access. Again, this leads to significant, complex firewall policies without context. More often, the entire network lacks visibility. For example, AWS teams understand the Amazon cloud but do not have visibility on-premise. We also have distributed responsibilities across multiple groups, which results in fragmented processes and workflows.

Security Principles: Data-flow Mapping

Network security starts with the data. Data-flow mapping enables you to map and understand how data flows within an organization. But first, you must understand how data flows across your hybrid network and between all the different resources and people, such as internal employees, external partners, and customers. This includes the who, what, when, where, why, and how your data creates a strong security posture. You are then able to understand access to sensitive data.

Data-flow mapping will help you create a baseline. Once you have a baseline, you can start implementing Chaos Engineering projects to help you understand your environment and its limits. One example would be a chaos engineering kubernetes project that breaks systems in a controlled manner.

Chaos Engineering

What prevents mapping sensitive data flows

What prevents mapping sensitive data flow? Firstly, there is an inability to understand how the hybrid network connects. Do you know where sensitive data is, how to find it, and how to ensure it has the minimum necessary access?

With many teams managing different parts and the rapid pace of application deployments, there are often no documents. No filing systems in place. There is a lack of application connectivity requirements. People don’t worry about documenting and focus on connectivity. More often than not, we have an overconnected network environment.

We often connect first and then think about security—also, the inability to understand if application connectivity violates security policy and lacks application-required resources. Finally, there is a lack of visibility into the cloud and deployed applications and resources. What is in the cloud, and how is it connected to on-premise and external Internet access?

network packet broker

Implementing Network Security and the Different Types of Telemetry

Implementing network security involves leveraging the different types of telemetry for monitoring and analysis. And for this, we have various kinds of packet analysis and telemetry data. Packet analysis is critical, involving new tools and technologies such as packet brokers. In addition, SPAN taps need to be installed strategically in the network infrastructure.

Telemetry, such as flow, SNMP, and API, is also examined. Flow is a technology similar to IPFIX and NETFLOW. We can also start to look at API telemetry. Then, we have logs that provide a wealth of information. So, we have different types of telemetry and different ways of collecting and analyzing it, and now we can use this from both the network and security perspectives. 

From the security presence, it would be for threat detection and response. Then, for the network side of things, it would be for network and application performance. So there are a lot of telemetries that can be used for security. These technologies were initially viewed as performance monitoring. However, security and networking have been merged to meet the cybersecurity use cases. So, in summary, we have flow, SNMP, and API for network and application performance, encrypted traffic analysis, and machine learning for threat and risk identification for security teams. 

The issues with packet analysis: Encryption.

The issue with packet analysis is that everything is encrypted, especially with TLS1.3. And at the WAN Edge. So how do you decrypt all of this, and how do you store all of this? Decrypting traffic can create an exploit and potential attack surface, and you also don’t want to decrypt everything.

Do not fully decrypt the packets.

One possible solution is not fully decrypting the packets. However, when looking at the packet information, especially in the header, which can consist of layer 2 and TCP headers. You can immediately decipher what is expected and what is malicious. You can look at the packers’ length and the arrival time order and understand what DNS server it uses.

Also, look at the round trip time and the connection times. There are a lot of understandings and features that you can extract from encrypted traffic without fully decrypting it. Combining all this information can be fed to different machine learning models to understand good and bad traffic.

You don’t need to decrypt everything.  So you may not have to look at the actual payload, but from the pattern of the packets, you can see with the right tools that one is a bad website, and another is a good website.

Key Points: Implementing network security

I have summarized how you might start implementing network security into four main stages. First, implementing network security begins with good visibility; this visibility must be combined with all our existing security tools. A packet broker can be used along with good automation. Finally, this approach must span all our environments, both on-premises and in the cloud.

Implementing network security
Diagram: A final note on implementing network security.
  • Stage 1: Know your infrastructure with good visibility

The first thing is getting to know all the traffic around your infrastructure. Once you know, they need to know this for on-premises, cloud, and multi-cloud scenarios. It would help if you had higher visibility across all environments. 

  • Stage 2: Implement security tools

With all environments, we have infrastructure that our applications and services ride upon. Several tools are used to protect. These tools will be placed in different parts of the network. As you know, we have firewalls, DLP, email gateways, and SIEM. We have other tools to carry out various security functions. These tools will not disappear or be replaced anytime soon but must be better integrated.

  • Stage 3: Network packet broker

You can introduce a network packet broker. So, we can have a packed brokering device that fetches the data and then sends the data back to the existing security tools you have in place. Essentially, this ensures that there are no blind spots in the network. Remember that this network packet broker should support any workload to any tools. 

  • Stage 4: Cloud packet broker

In the cloud, you will have a variety of workloads and several tools, such as SIEM, IPS, and APM. These tools need access to your data. A packet broker can be used in the cloud, too. So, if you are in a cloud environment, you need to understand the native cloud protocols, such as VPC mirroring; this traffic can be brokered, allowing some transformation to happen before we move the traffic over. These transformant functions can include de-duplication, packet slicing, and TLS analyses.

This will give you complete visibility into the data set across VPC at scale, eliminating any blind spots and improving the security posture by sending appropriate network traffic, whether packets or metadata, to the tools stacked in the cloud. 

Implementing robust network security measures is of utmost importance in an era where cyber threats continue to evolve and become more sophisticated. Individuals and organizations can fortify their network security posture by assessing vulnerabilities, establishing firewalls and intrusion detection systems, enforcing strong authentication and access controls, conducting regular software updates, and implementing data encryption and secure communication protocols. Remember, network security is an ongoing process that requires continuous monitoring and adaptation to stay one step ahead of potential threats.

Network Security Components

Section 1: Firewalls – The First Line of Defense

Firewalls act as a barrier between your internal network and the outside world. They analyze incoming and outgoing network traffic and block potentially harmful data packets. By setting up firewalls properly, you can control access to your network and protect against unauthorized access attempts.

Section 2: Encryption – Securing Your Data

Encryption converts sensitive data into an unreadable format called ciphertext using cryptographic algorithms. This ensures that even if an attacker gains access to your data, they won’t be able to make sense of it. Implementing encryption protocols, such as SSL/TLS, for data transmission and using encryption algorithms for stored data adds an extra layer of protection.

Section 3: User Authentication – Verifying Legitimate Access

User authentication is vital to prevent unauthorized access to your network. Implementing strong password policies, multi-factor authentication, and regularly reviewing user privileges are effective measures to ensure that only authorized individuals can access your network resources.

Section 4: Intrusion Detection Systems – Detecting and Responding to Threats

Intrusion Detection Systems (IDS) monitor network traffic and identify suspicious activities or potential security breaches. IDS can be network- or host-based, providing real-time alerts and enabling swift response to mitigate potential risks.

Section 5: Network Monitoring – Keeping an Eye on Your Network

Network monitoring tools enable you to monitor network traffic, identify anomalies, and detect potential security incidents. You can proactively address any vulnerabilities by constantly monitoring your network, ensuring your system’s security and integrity.

Section 6: Best Practices for Network Security

To enhance your network security, it is essential to follow best practices. Some key recommendations include regularly updating software and firmware, conducting security audits, performing regular backups, educating employees on cybersecurity awareness, and staying informed about the latest security threats and solutions.

Summary: Implementing Network Security

In today’s interconnected world, where digital communication and data exchange are the norm, ensuring your network’s security is paramount. Implementing robust network security measures not only protects sensitive information but also safeguards against potential threats and unauthorized access. This blog post provided you with a comprehensive guide on implementing network security, covering key areas and best practices.

Section 1: Assessing Vulnerabilities

Before diving into security solutions, it’s crucial to assess the vulnerabilities present in your network infrastructure. Conducting a thorough audit helps identify weaknesses such as outdated software, unsecured access points, or inadequate user permissions.

Section 2: Firewall Protection

One of the fundamental pillars of network security is a strong firewall. A firewall is a barrier between your internal network and external threats, monitoring and filtering incoming and outgoing traffic. It serves as the first line of defense, preventing unauthorized access and blocking malicious activities.

Section 3: Intrusion Detection Systems

Intrusion Detection Systems (IDS) play a vital role in network security by actively monitoring network traffic, identifying suspicious patterns, and alerting administrators to potential threats. IDS can be network- or host-based, providing real-time insights into ongoing attacks or vulnerabilities.

Section 4: Securing Wireless Networks

Wireless networks are susceptible to various security risks due to their inherent nature. Implementing robust encryption protocols, regularly updating firmware, and using unique and complex passwords are essential to securing your wireless network. Additionally, segregating guest networks from internal networks helps prevent unauthorized access.

Section 5: User Authentication and Access Controls

Controlling user access is crucial to maintaining network security. Implementing robust user authentication mechanisms such as two-factor authentication (2FA) or biometric authentication adds an extra layer of protection. Regularly reviewing user permissions, revoking access for former employees, and employing the principle of least privilege ensures that only authorized individuals can access sensitive information.

Conclusion:

Implementing network security measures is an ongoing process that requires a proactive approach. Assessing vulnerabilities, deploying firewalls and intrusion detection systems, securing wireless networks, and implementing robust user authentication controls are crucial steps toward safeguarding your network. By prioritizing network security and staying informed about emerging threats, you can ensure the integrity and confidentiality of your data.