10 Network Security Engineer Interview Questions and Answers for Security Engineers

flat art illustration of a Security Engineer
If you're preparing for security engineer interviews, see also our comprehensive interview questions and answers for the following security engineer specializations:

1. What procedures would you implement to track and analyze potential network threats in real-time?

One of the most important procedures to track and analyze potential network threats in real-time is to implement a comprehensive Intrusion Detection System (IDS) and Security Information and Event Management (SIEM) system. By doing this, we can monitor network events, identify potential security threats, and respond to security-related incidents in a timely and effective manner.

To ensure effective and accurate threat analysis, I would ensure that the IDS and SIEM systems are properly configured and maintained according to industry best practices, including defining normal network behavior and setting up alerts for any deviations. I would also implement log file analysis and packet capture tools to collect and analyze network activity data and detect potential threats that may otherwise go unnoticed.

Another important procedure would be to leverage threat intelligence from external sources such as industry-leading vendors, government agencies, and the security community at large. This would assist in identifying and tracking potential new threats in real-time, while also improving the overall accuracy and efficiency of the threat detection process.

In order to track the progress of the implemented procedures, I would establish Key Performance Indicators (KPIs) to measure the effectiveness of the system. For example, I would track the number of false positives and false negatives, the number of blocked attempts, and the time taken to respond to security-related incidents among others.

  1. Configuration and maintenance of comprehensive IDS and SIEM systems.
  2. Log file analysis and packet capture tools to collect and analyze network activity data.
  3. Leveraging threat intelligence from external sources such as industry-leading vendors, government agencies, and the security community at large.
  4. Establishing Key Performance Indicators (KPIs) to measure the effectiveness of the system.

2. How would you ensure that firewalls and other security tools are properly configured and up-to-date?

As a Network Security Engineer, my priority is to ensure that firewalls and other security tools are properly configured and up-to-date to safeguard the organization's sensitive data. I would adopt the following steps to ensure their effectiveness:

  1. Regular Monitoring: I would regularly monitor the firewalls and security tools to ensure that they are functioning correctly and according to industry standards. This would help me identify any configuration issues or vulnerabilities that need to be addressed.
  2. Automated Testing: I would set up automated testing tools to perform regular checks on firewall and security configurations for any gaps in security. This would help me identify and address potential threats as quickly as possible.
  3. Updates: I would ensure that all firewalls and security tools are updated with the latest operating system patches and security updates. I would also ensure that any custom configurations are updated according to current best practices.
  4. Training: Regular training for IT staff would also play a crucial role in maintaining the security standards of the organization. This would involve training them on the latest security technology and how to configure firewalls and security tools properly to prevent any potential breaches.
  5. Documentation: I would maintain detailed documentation of all network security configurations, updates, and any risks or threats that were identified and addressed. This documentation would be used for future reference and to identify any areas for improvement.

Overall, it is essential to keep firewalls and security tools updated and configured correctly to protect the organization's sensitive information. Regular monitoring, automated testing, updates, training, and documentation can help ensure that the network remains secure and data breaches are prevented.

3. Can you give an example of a time when you resolved a major security breach, how did you handle the situation?

One significant security breach I handled occurred at my previous job at XYZ Corporation. We discovered that one of our employees had downloaded a virus onto their company-issued laptop, which had spread throughout our entire network.

  1. The first step I took was to isolate the affected devices from our corporate network to prevent further damage. We immediately shut down the infected server and all devices connected to it. This included disconnecting all employees from the internet and blocking all incoming and outgoing traffic from our network.

  2. Next, I worked with our IT team to identify the source of the virus and the extent of the damage it caused. We found that the virus had spread to multiple devices and had already begun encrypting files on affected computers.

  3. I then collaborated with our cybersecurity professionals to develop a plan to contain and eradicate the virus. As a team, we implemented various strategies to identify and remove the virus from our systems.

  4. We also conducted a thorough investigation to determine how the virus was able to infiltrate our network. We discovered that it was likely spread through a malicious link in a phishing email that the employee had clicked on. We then implemented mandatory cybersecurity awareness training for all employees to prevent similar incidents from happening in the future.

  5. As a result of our quick response and thorough intervention, we were able to contain the virus within a few hours and prevent any significant data loss. We learned from this incident and took the necessary measures to prevent future security breaches in our organization.

4. How would you approach securing remote network access for employees working from home?

Securing remote network access for employees working from home is a critical aspect of network security. To approach this task, I would follow a step-by-step approach:

  1. Firstly, I would assess the security risks associated with remote access, taking into account the nature of the organization, types of data being accessed, and the remote devices being used. I would then develop a comprehensive risk management plan, which would include potential threats, consequences, and countermeasures to prevent such threats.
  2. Secondly, I would implement two-factor authentication measures, including the use of hardware tokens or biometric identification. I would also ensure all remote access points are using encrypted VPN connections. Such measures would prevent or reduce the risks of unauthorized access to the network.
  3. Thirdly, I would deploy a security solution that enables employees to securely access the network from their remote locations. This includes deploying network access control (NAC) systems and firewalls to filter out malicious traffic and keep employees' systems current and secure.
  4. Fourthly, I would educate employees on network security, including phishing and social engineering attacks. I would also ensure they are aware of proper password management, such as changing passwords on a regular basis and using complex passwords.
  5. Finally, I would regularly evaluate and audit remote access connections, to ensure compliance with the company's security policies and identify any potential security warnings or infringements. Data or concrete results would then be used to make required adjustments and scale up or down to meet company needs.

5. When setting up a security protocol, how do you balance the practical with the secure?

When setting up a security protocol, it is crucial to balance practicality with security. The practical aspect includes factors such as user experience, accessibility, and functionality, while security involves the protection of sensitive data and information.

  1. Firstly, I ensure that I fully understand the client's requirements and their overall security goals. This enables me to identify the priority areas where enhanced security measures are needed.

  2. Once I have identified the priority areas, I research and leverage industry best practices and standards, such as ISO 27001 and NIST frameworks, to design an effective security protocol.

  3. I also conduct a risk assessment to identify potential threats and vulnerabilities that may impact the security protocol. Based on the results, I adjust the balance between practicality and security.

  4. I collaborate with the development team to ensure that the security protocol's practical aspects do not hinder the software's functionality or user experience. This process involves testing various scenarios and configurations to make sure that the security protocol is practical and does not negatively impact the software.

  5. Lastly, I regularly review and update the security protocol to address emerging threats and potential vulnerabilities. Using advanced threat intelligence and penetration testing tools, I analyze security logs to identify security incidents and make necessary adjustments to the security protocol.

Through this approach, I have been successful in designing and implementing highly effective security protocols that balance practicality and security. At my previous role, I implemented a new security protocol that reduced the number of reported security incidents by 70% within the first three months of deployment. The practical adjustments we made did not negatively impact the user experience, and ultimately, improved the overall functionality of the software.

6. What specific tools and technologies have you used to monitor network security?

During my experience as a Network Security Engineer, I have worked with several tools and technologies to monitor network security. Some of the most common ones include:

  1. SolarWinds Security Event Manager (SEM). This tool allowed me to capture and analyze security events that occurred on the network. For instance, I set up SEM to collect logs from all of our network devices and servers. Then, I configured it to send real-time alerts whenever it detected suspicious activity, such as failed login attempts or port scans. As a result, I was able to respond to potential threats quickly and prevent security breaches from occurring.
  2. Nessus Vulnerability Scanner. I used Nessus to scan our network for vulnerabilities that could be exploited by attackers. The tool performed various checks on our systems, such as identifying missing patches, weak passwords, and open ports. Once it completed the scan, it generated a report that highlighted the vulnerabilities and provided recommendations for remediation. By acting on these recommendations, we were able to significantly reduce our risk of being compromised.
  3. Snort Intrusion Detection System (IDS). Snort is an open-source IDS that I used to detect and prevent intrusions on our network. It worked by analyzing network traffic in real-time and looking for patterns that matched known attack signatures. If it detected an attack, it could either block the traffic or alert me for further investigation. I found Snort to be an effective way to protect our network from common attacks, such as SQL injection and cross-site scripting.

These tools allowed me to gain a comprehensive view of our network security posture and respond to potential threats quickly. As a result, we were able to reduce our risk of cyber attacks and keep our data safe.

7. Have you ever audited a network's security protocols? What was the result and how did you resolve it?

Yes, I have audited a network's security protocols in my previous role as a Network Security Engineer at XYZ Corporation. During the audit, I discovered that the firewall was not properly configured, which posed a major security risk to the organization.

  1. To resolve this issue, I immediately updated the firewall settings and implemented two-factor authentication for all sensitive data access.
  2. Additionally, I recommended that the organization conduct regular security awareness training for all employees to prevent future vulnerabilities.
  3. As a result of my efforts, the organization saw a significant decrease in the number of security breaches and attacks, with only one minor incident reported in the following year.

I believe that proactive measures such as regular audits, updates, and training are essential for maintaining a secure network and ensuring the protection of sensitive data.

8. Can you walk me through your experience setting up a Virtual Private Network (VPN)?

During my time at Company X, I was tasked with setting up a VPN to connect remote employees and branch offices to the company network. I began by designing a network architecture that would ensure data confidentiality, integrity, and availability by implementing encryption algorithms, firewalls, and intrusion detection systems.

  1. The first step was to choose the right VPN technology to use. I opted for OpenVPN as it provided a good balance between security and performance.
  2. Next, I created a Certificate Authority (CA) server to issue digital certificates to users and devices that would authenticate their identity when connecting to the VPN.
  3. I then set up a VPN server on a dedicated machine that would act as the gateway for all VPN traffic.
  4. To increase security, I configured the server to only allow connections via the OpenVPN protocol over UDP port 1194, which I also customized to prevent common attacks like port scanning and DoS attacks.
  5. After creating user accounts and generating client configuration files, I distributed them to authorized employees, who could then install the OpenVPN client software on their devices and connect securely to the VPN.
  6. To ensure that data was transmitted securely, I implemented Transport Layer Security (TLS) to encrypt all traffic between the VPN server and client devices.
  7. I also created a log server to monitor and analyze any suspicious activity on the VPN, which helped me quickly detect and respond to any potential security breaches.
  8. Finally, I conducted several penetration tests to confirm the effectiveness of the VPN security controls and made some further improvements to strengthen it where necessary.

As a result of my efforts, Company X was able to securely connect remote employees and branch offices to the company network, improving productivity, and collaboration while minimizing the risk of data breaches or unauthorized access. The VPN also improved the overall security posture of the organization, ensuring that sensitive data and information remained confidential and well-protected.

9. How do you keep up-to-date with new security threats and potential vulnerabilities in networks?

Staying up-to-date with new security threats and potential vulnerabilities in networks is a top priority for me as a security engineer. Here are a few methods I use:

  1. Following industry news and updates: I make sure to stay up-to-date on the latest security news and trends by regularly reading industry publications and attending conferences and webinars. I also subscribe to various security newsletters to receive updates on potential threats and vulnerabilities.
  2. Participating in online security communities: To stay current, I participate in various online security communities and forums where professionals share their observations and discuss recent threats which help me to be more alert and respond to new threats quickly.
  3. Testing and experimentation: I continuously experiment with new and emerging technologies to identify any possible vulnerabilities in our network system.
  4. Security assessments: We conduct periodic security assessments with third-party security experts to make sure our security measures meet industry best practices and standards.
  5. Continuing education: I attend various security-related training and certification courses to maintain and improve my knowledge of the security landscape.

By following these methods, I've been able to keep my organization's network secure from potentially harmful threats, and I am confident that I will continue to do so in the future.

10. Have you ever conducted a pen test or engaged in ethical hacking? If so, could you describe the experience?

Yes, I have conducted several pen tests in my previous role as a Network Security Engineer at XYZ Company. One of the most challenging pen tests I performed was for a financial institution that had never undergone any security testing before.

  1. First, I thoroughly researched their systems and infrastructure to understand potential vulnerabilities.
  2. Next, I conducted a series of tests to try to exploit those vulnerabilities, including penetration testing and ethical hacking.
  3. Throughout the process, I documented my findings and worked with the company's IT team to remediate any issues that were identified.
  4. One of the major vulnerabilities I identified was an open port on their web server that allowed for unauthorized access to sensitive financial data.
  5. After informing the IT team of this vulnerability, they promptly closed the open port and implemented additional security measures to prevent similar issues in the future.
  6. As a result of my pen testing, the financial institution was able to strengthen their security posture and prevent potential data breaches.

Overall, conducting this pen test allowed me to apply my technical expertise and problem-solving skills to identify vulnerabilities and recommend effective solutions, while also helping the client to avoid potential cyber attacks and data breaches.


In conclusion, as a network security engineer, you must be ready to answer tough interview questions related to network security. This blog post has identified 10 common questions that can help prepare you for a successful interview. Additionally, it’s essential to write a great cover letter and prepare an impressive CV, which can help you stand out from other candidates. If you are actively looking for a new job, check out our remote Security Engineering job board to find opportunities that match your skills and expertise. Good luck with your job search!

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