30 VPN Interview Questions & Answers
Below is a list of our VPN interview questions. Click on any interview question to view our answer advice and answer examples. You may view 5 answer examples before our paywall loads. Afterwards, you'll be asked to upgrade to view the rest of our answers.
Table of Contents
General
1. When vetting VPN Product Vendors, what are some of the tougher questions you ask them to qualify their solutions and determine if they are appropriate for your requirements?
How to Answer
One of the roles of a VPN system specialist is to work with vendors to select the appropriate technology for their requirements. They then need to continue the relationship with the vendor for ongoing support, upgrades, and other issues. Striking a balance between these is critical. When answering this question, you should demonstrate your ability to appropriately vet the vendor solution without antagonizing them or compromising the relationship you need after selecting their products.
Written by William Swansen on October 25th, 2021
Answer Example
"When interviewing vendors to select a VPN, I try to strike a balance between making sure their products fit my needs while developing a working relationship between them and our organization. For example, many vendors claim to be IPSEC-compliant. To verify this, I ask a question like 'Can you list the other network security products with which you can communicate.' Also, as a customer, I want to know how automatic the key exchange mechanism is. In a perfect world, it would be automatic. Another question I use is that if a Virtual Network Perimeter (VNP, not VPN) is used, how easy is it to deploy the software to remote users?"
Written by William Swansen on October 25th, 2021
Operational
2. VPNs have a reputation for solving most, if not all, network security issues. Are there any unreasonable expectations for a VPN or issues it doesn't address?
How to Answer
As a VPN technology specialist, it is easy to become enamored with the technology and fall into the trap of thinking VPNs can solve all network security issues. Employers appreciate people who can see both sides of an issue and expertly discuss the shortcomings of technologies, such as VPN. You can continue to advocate for VPNs and the benefits they bring to a network while also making the company management team aware of its vulnerabilities. It would help if you also were prepared to answer questions about overcoming the vulnerabilities or taking measures to prevent them.
Written by William Swansen on October 25th, 2021
Answer Example
"When firewalls were first introduced, they became a must-have in the network security strategy. This created a false impression that all internet security problems were solved with a firewall. VPNs were developed to resolve the issues firewalls didn't address and plug the holes they left in the network security. This created the illusion that when a VPN is in place, you don't need firewalls. This is incorrect. For example, VPNs cannot enforce security policies, detect malice or mistakes, and regulate user access. VPNs can only do what they were meant to do: keep communications private through encryption and disguising the network servers real IP addresses."
Written by William Swansen on October 25th, 2021
Operational
3. In what scenarios are site-to-site and remote access VPN employed?
How to Answer
This question is meant to test your knowledge of VPN technology, especially when accessing internal resources from a remote location. As a VPN systems specialist, you can anticipate being asked mostly technical or operational questions during an interview. These address specific topics of leveraging VPN technology over the network and are meant to explore your qualifications for this role. Reviewing VPNs and general network technology operations before the interview is highly recommended and will better prepare you for these types of questions.
Written by William Swansen on October 25th, 2021
Answer Example
"A site-to-site VPN enables users in multiple locations to establish secure connections with each other over the internet. This masks the user's IP address and secures the data through encryption. Remote access VPN allows users outside of the company location to connect to the company's internal network through a secure tunnel established over the internet. The remote user can then access internal, private web pages and perform various IP-related network tasks as if they were onsite. Remote Access VPN is accomplished using either IPsec or SSL VPN."
Written by William Swansen on October 25th, 2021
Operational
4. In your opinion, is a VPN a long-term solution or a short-term stopgap to an immediate security threat?
How to Answer
As a VPN system specialist, you'll be asked to provide strategic and tactical solutions to security issues. The interviewer asks you this question to determine how you employ a VPN since it can address immediate threats or threats anticipated during the organization's ongoing operations. The VPN is only one of many tools you can use to secure an organization's network infrastructure and the information transmitted across it.
Written by William Swansen on October 25th, 2021
Answer Example
"In my opinion, VPNs are long-term solutions. VPNs are often ubiquitous and usually transparent to the user. Once installed, they rarely go away because the threats and security challenges VPNs address never go away. VPNs exist from the desktop to the server, at the IP packet level, as well as the application data level."
Written by William Swansen on October 25th, 2021
Operational
5. Are there applications or environments in which VPNs may be detrimental and cause more harm than they do good?
How to Answer
It is natural for business leaders who are not familiar with technology to be skeptical about its use and benefits. Asking how the VPN may be detrimental to the network is a natural question you should expect during an interview. Nothing is without faults, and you should be able to talk about situations in which the VPN is not applicable. Make sure you don't fabricate something that is either unrealistic or not relevant to the company's environment.
Written by William Swansen on October 25th, 2021
Answer Example
"In general, the answer is no. However, suppose a VPN is used on a system behind a firewall to a system outside the firewall. In that case, the firewall cannot enforce an organization's security policy beyond connection rules. VPNs should also not be used in situations where there is no confidential or proprietary information being transmitted across the network, and the network performance needs to be optimized."
Written by William Swansen on October 25th, 2021
Operational
6. When deciding whether to use VPN, what items do you consider? What do you then consider when selecting, deploying, and maintaining VPN?
How to Answer
When interviewing for a role to manage a Virtual Private Network, you will be asked various questions. The interviewer is likely to start with a similar question to determine what criteria you use when selecting a VPN and how you implement and manage it. Assuming you're qualified for this role, this should be easy for you to answer. It is recommended that before the interview, you research the company's existing technology solutions so you can align your answers with what they already have in place. Don't be afraid to suggest new technologies which will improve the performance of their network. This will set you apart from other candidates.
Written by William Swansen on October 25th, 2021
Answer Example
"There are several different criteria I use to determine if a VPN is required to enhance the security of a network, especially if there are already firewalls in place. My research indicated that you are currently using an IPsec solution. I favor this approach, even though this technology is continuing to evolve. Some of the specific criteria I use include:
- Does the existing network security solution protect the network, or are additional measurements required?
- If the VPN solution is not currently part of the firewall, will it work with the existing firewall?
- Will the proposed solution be Interoperable with other IPsec compliant vendors?
- Does it have strong encryption with long key lengths?
- Does the VPN product work both with and without trust?
- Does the VPN support the automatic creation of user-level VPNs for mobile users?
- Has the VPN been certified?
- How will the VPN impact the performance of the network and specific applications?
- What is the cost of implementing and maintaining the VPN?"
Written by William Swansen on October 25th, 2021
Operational
7. What are the reasonable expectations as to what a VPN can do to protect an organization's network and proprietary information?
How to Answer
Any employee who works in information technology is vulnerable to becoming enamored with the technology and the problems it solves. This can potentially blind you to some of the technology's shortcomings. Business leaders depend on their IT staff to provide realistic assessments of how the technology performs, the problems it solves, and the threats it can protect them against. When asked this type of question, you should provide a realistic example of what a VPN can do. The interviewer will immediately recognize if you're trying to oversell the solution.
Written by William Swansen on October 25th, 2021
Answer Example
"The main function of a virtual private network is to provide end-to-end network security and privacy. It uses robust cryptography to secure and mask the content moving across the network and the identity of the users. However, security threats continuously evolve, and hackers are becoming more sophisticated in penetrating firewalls and VPNs. The staff supporting the security of a network must maintain vigilance and stay up to date on these evolving threats. Set it and forget it is not a workable strategy when it comes to network security."
Written by William Swansen on October 25th, 2021
Technical
8. What Is meant by the term "ËœTransform Set'?
How to Answer
As the interview for a VPN role progresses, you will continue to be asked technical questions about the terminology, technology, processes, and procedures used in this job. These questions can range from very easy to very complex. Since there is no standard interview manual available, the interviewer can ask these questions at any time during the interview. The last way to be prepared for this is to review the terminology, processes, and procedures used in this job and be familiar with them. Practicing these types of questions will also help you be ready to respond to the interviewer appropriately.
Written by William Swansen on October 25th, 2021
Answer Example
"The term 'transforms set' refers to a technology used within the IPsec protocol. It defines a combination of security protocols and algorithms used during the IPsec security association (SA) negotiation. Using this protocol, the network nodes agree to use a particular transform set to establish a secure connection for exchanging data."
Written by William Swansen on October 25th, 2021
Technical
9. What are the different modes for Secure Sockets Layer Virtual Private Network or SSL VPN?
How to Answer
It is common in the technology world for protocols, technology, and other items to have several different versions or modes. As a seasoned VPN professional, you should be able to discern between these modes and discuss each one. Interviewers will ask you a question like this to see how detailed your knowledge is. Since this is a technical question, your answer should first define each of the modes and then compare them discussing their features and benefits.
Written by William Swansen on October 25th, 2021
Answer Example
"There are three different modes for secure socket layer virtual private networks or SSL VPNs. The first is the clientless mode. This works at layer 7 of the network protocol and provides secure access to resources and content across the web. The clientless mode also supports common Internet file systems and can access databases and other online tools. The next mode is the thin client mode which also works at layer 7. This mode provides additional access to services such as Telnet, Secure Shell, Simple Mail Transfer Protocol, Internet Messaging Access Protocol, and Post Office Protocol, also known as POP3. The thin client is provisioned via a Java applet. The final mode is the thick client mode. This works at layer 3 and is also known as the tunnel mode. This mode provides all the services previously mentioned and is provisioned via dynamically downloaded VPM client software."
Written by William Swansen on October 25th, 2021
Technical
10. What Is a Cisco Easy VPN, and what are its benefits?
How to Answer
Cisco is the major player in networking technology and dominates the space in many areas. As a VPN professional, you likely already have several different Cisco certifications. If not, it is highly recommended that you attain these. The knowledge you gain during your Cisco certification process will help enhance your skills as a VPN professional, and the certifications will enhance your chances of getting hired. It will also provide you with the knowledge to answer network questions related to Cisco technologies similar to this one.
Written by William Swansen on October 25th, 2021
Answer Example
"Cisco Easy VPN is a remote access VPN implemented within an IPsec. Cisco has made this technology easy to implement, and there is the minimal configuration required at the client site. This makes it useful when setting up VPNs at remote sites such as home offices where the network technical team is not present and does not have direct access to the user's equipment. Cisco Easy VPN also allows the network support team to establish centralized security policies on the VPN server which can then be pushed out to the entire network."
Written by William Swansen on October 25th, 2021
Technical
11. What commands do you use to check the status of a VPN tunnel's phases 1 & 2?
How to Answer
During an interview for a VPN role, you may be asked to demonstrate the commands you use to manage VPN networks. These requests can be in the form of a question, or you may be required to sit in front of a terminal and demonstrate the commands you use to manage the network. As an experienced VPN professional, this should not be an issue. However, there may be some commands you don't typically use but which are important for the organization or the interviewer will use to test your skills. It is recommended that you brush up on your commands before the interview to be ready for these types of questions or requests.
Written by William Swansen on October 25th, 2021
Answer Example
"The commands I use to check the status of the tunnel faces are as follows:
Phase 1 - show crypto isakmp sa
Phase 2 - show crypto ipsec sa"
Written by William Swansen on October 25th, 2021
Technical
12. Can you explain the difference between static crypto maps and dynamic crypto maps?
How to Answer
Many times, when an interviewer asks you a technical question, it will be in the form of comparing two similar but different technologies. The best way to respond to this question is to define each technology and then compare and contrast them. You may want to provide an example of how you use these in your daily work. Remember to keep your answer direct and to the point and avoid using technical terms the interviewer may not understand.
Written by William Swansen on October 25th, 2021
Answer Example
"Both static and dynamic crypto maps are technologies used to identify network peers when transmitting data in IPsec sites to VPNs. Static crypto maps are used when the peers are already predetermined and identified. Dynamic crypto maps are used when the peers are not predetermined. Both of these technologies use IPsec to remote access VPNs. Alternatives to using crypto maps are VTIs or Virtual Tunnel Interfaces. These are established in advance and avoid using older, less elegant technologies including access lists and crypto maps."
Written by William Swansen on October 25th, 2021
Technical
13. Can you explain DMVPN?
How to Answer
The interviewer will ask you this question for two reasons. One is to ensure that you understand some of the more common technologies used within VPNs. The second is to give them an example of how you explain complex topics to individuals with non-technical backgrounds. They expect your answer to be clear and concise and absent of any jargon, acronyms, or complex terminology which may be difficult to understand. This is important since you will be collaborating with people from outside of the technology organization in this role.
Written by William Swansen on October 25th, 2021
Answer Example
"DMVPN stands for Dynamic Multipoint Virtual Private Network. This protocol allows an IPsec VPN network to scale across different topologies. These include hub-to-spoke and spoke-to-spoke. DMVPN optimizes the performance and reduces the latency between the nodes on the network. Some of the benefits this protocol provides include reducing router configuration on the hub, support for dynamic routing protocols, enabling multicast traffic from the hub to the spokes, and establishing an IPsec tunnel between the spokes, thereby avoiding having to send traffic through the hub."
Written by William Swansen on October 25th, 2021
Technical
14. What Is Ike, and what communication port does this protocol use?
How to Answer
Many interview questions will have several questions embedded within them. It is critically important to listen to the interviewer's complete question before beginning to formulate your answer. Many job candidates are nervous during an interview. This causes them to begin answering the interviewer's question before they have finished asking it. This makes them appear unprofessional and may result in them not providing the information the interviewer is requesting. A good practice is to pause for 2 seconds after the interviewer has stopped speaking before you begin your answer.
Written by William Swansen on October 25th, 2021
Answer Example
"Ike is a protocol that defines a mechanism for creating and exchanging keys. Ike implements both the Oakley and SKEME key exchanges. These are key-agreement protocols that allow authenticated parties to exchange keying material across an insecure connection. Both of the protocols function within the Internet Security Association and Key Management Protocol (ISAKMP) framework. Ike uses UDP port 500 to communicate."
Written by William Swansen on October 25th, 2021
Technical
15. What is a Diffie-Hellman key, and how does it work?
How to Answer
There are many different technologies used to implement, manage, and utilize VPN. As a VPN professional, you are expected to know most of these and define them. If, for some reason, you're unfamiliar with the technology that the interviewer asks you about, immediately admit this and then describe how you would go about locating the information. When discussing these technologies, you may want to compare and contrast them and even provide an example of how they illustrate your answer.
Written by William Swansen on October 25th, 2021
Answer Example
"A Diffie-Hellman Key is a public key use for encryption within a virtual private network or VPN. This key is used in conjunction with a private key to encrypt the transmission over the network. When setting up a transmission, each side exchanges the public Diffie-Hellman Key and creates a shared key using RSA. The keys are then used to send the transmission. Even if the public key is intercepted, the intruder cannot read the transmission without the private key."
Written by William Swansen on October 25th, 2021
Technical
16. Can you explain Next Hop Resolution Protocol (NHRP) and how it is used in VPN?
How to Answer
Any time you're asked to explain a concept, process, or term used in the role you are interviewing for, the interviewer is trying to accomplish two objectives. The first is to test your knowledge and make sure you are qualified for the position. The second is to understand how you communicate. This latter objective is just as important as the first because a major focus for your job will be to discuss networking terms with people throughout the organization. These include both technical and non-technical individuals. The most successful people within an organization are those who are the best communicators.
Written by William Swansen on October 25th, 2021
Answer Example
"Next Hop Resolution Protocol or NHRP is a Layer 2 protocol used to map a tunnel IP address to a Non-Broadcast Multiple Access or NBMA address. The way it works is that the hub maintains an NHRP database of the public addresses for each spoke of the network. When an individual spoke boots up, it registers its real address to the hub and queries the hub's NHRP database for the real addresses of the other spokes. This allows each spoke to build direct tunnels to each other, bypassing the hub and improving the performance of the network."
Written by William Swansen on October 25th, 2021
Technical
17. Can you walk me through the steps in an SSL handshake?
How to Answer
Being asked to walk the interviewer through a process is a common question you will encounter during an interview. The interviewer probably is not concerned about the specific steps required in the process, but rather your ability to break them down and describe each event clearly and concisely. The trap in this type of question is providing too much information and rambling on about the process. Keep your answer direct and to the point, describing each step with as few words as possible in clear, easy-to-understand language.
Written by William Swansen on October 25th, 2021
Answer Example
"A VPN SSL connection is established through a process known as a handshake. It starts when the client sends a 'Hello' message, which contains the SSL version that the client supports, the order the client prefers the versions, crypto algorithms supported by the client, and a random number. The server responds with its Hello message with similar information and the Session ID. It also sends an authentication certificate known as a PKI. The client will then send its certificate if the server has also requested client authentication in the server hello message. Next, the client will send a Client Key Exchange (CKE) message after calculating the premaster using the random values exchanged by the server and client, encrypting it with the server's public key. The server can decrypt the premaster secret using its private key. Both client and server perform symmetric series of steps generating session keys that encrypt and decrypt data exchanged during the SSL session. The client sends a Change Cipher Suite message letting the server know that future messages will be encrypted using the session key. Once the handshake is completed, the client sends a Client Finish message, both before and after the server acknowledges the Change Cipher Suite message."
Written by William Swansen on October 25th, 2021
Technical
18. Are there more than one SSL VPN mode, and if so, can you describe them?
How to Answer
Knowing the various modes of SSL is a key piece of knowledge a VPN System specialist must possess. It would be best if you described them in simple, easy-to-understand language. This will also demonstrate your ability to communicate across the organization. Avoid using acronyms or technology-specific terminology when answering interview questions since you do not know how well the interviewer understands the technology. You can take a clue from how they ask the questions and the terminology that they use.
Written by William Swansen on October 25th, 2021
Answer Example
"There are three modes in which SSL VPN can be deployed. These all relate to the type of client being used. The first is the clientless mode; it works at Layer 7 in the network stack, providing secure access to web resources and web-based content. This mode is commonly used for accessing content via a web browser. One drawback to this mode is that it does not provide access to TCP connections such as SSH or Telnet.
The next mode is thin client; it also works at Layer 7, known as port forwarding. This SSL mode is delivered via a Java applet downloaded from the SSL appliance when a session is established. Thin client mode provides access to services such as Telnet, Secure Shell (SSH), Simple Mail Transfer Protocol (SMTP), Internet Message Access Protocol (IMAP), and Post Office Protocol (POP3.)
The final mode is thick client mode; it works at Layer 3 and is also known as a full tunneling client. This mode provides application support through dynamically downloaded SSL client software from a VPN server appliance. This mode delivers an easy-to-support SSL VPN tunneling connection and full access to any application."
Written by William Swansen on October 25th, 2021
Technical
19. Can you define SSL VPN and discuss how it differs from IPsec VPN?
How to Answer
Discussing different aspects of a VPN and comparing and contrasting them is another form of a technical question. These types of questions differentiate well-qualified candidates from individuals who are only familiar with the basic terms and processes used in this job. It is helpful if you know the company's operations and the type of protocols and processes they use to manage their network before the interview. This will help you to frame your answers, so they are relevant to the job the company is asking you to perform.
Written by William Swansen on October 25th, 2021
Answer Example
"SSL VPN is used to provide remote access from any internet-enabled device through a web browser, using its embedded SSL encryption. It does not require any special client software. When an IPsec VPN connection is initiated, it uses a VPN client software application and requires the prior installation of the special client software. IPsec is more secure than SSL, but it also requires more overhead and therefore is more cumbersome."
Written by William Swansen on October 25th, 2021
Technical
20. What Are Crypto Maps, and how are they used?
How to Answer
The degree of difficulty of the technical questions asked during an interview will differ depending on the type of role you are interviewing for. The interviewer will stick to basic questions for entry-level positions, focusing on general terminology, practices, and procedures. For advanced VPN systems specialist roles, the interviewer is likely to ask more in-depth technical questions. These address issues that you can only learn about after years of experience or advanced studies.
Written by William Swansen on October 25th, 2021
Answer Example
"A crypto map is used to consolidate the various parts used to set up the IPsec SAs. These include which traffic should be protected by IPsec, known as the crypto access list, where to send the traffic, and what IPsec SA to use. Multiple interfaces can use the crypto map to simplify the management of the VPN. Conversely, multiple crypto maps can be used by a single interface to prioritize traffic."
Written by William Swansen on October 25th, 2021
Technical
21. What Are Security Associations (SA), and how are they used?
How to Answer
This is an example of a follow-up question. During the interview, you may have mentioned security associations in some of your answers. The interviewer can ask these at any time during the interview, either immediately after you use a term or sometime later. One purpose of this type of question is to clarify your answer or a term you've used earlier. Another purpose is to ensure that you are answering the interviewer's questions consistently throughout the interview. Being honest and truthful and not fabricating answers will ensure that you are consistent when answering questions during the interview.
Written by William Swansen on October 25th, 2021
Answer Example
"Security Associations (SAs) define the protocols and algorithms to be applied to IP packets during transmission and specify the keys to be used by the sending and receiving nodes. SAs are unidirectional and are established per the security protocol used in the IPsec headers, either AH or ESP."
Written by William Swansen on October 25th, 2021
Technical
22. Can you describe how ISAKMP and IKE protocols work?
How to Answer
As the interview progresses, the technical questions you will be asked will become more difficult and more specific to the company's operations with whom you are interviewing. One way you can prepare for this is to research the company's operations and try to learn as much as you can about the technology they employ, their processes, and some of the products they have incorporated into their IT strategy. Being familiar with this will help you formulate your answers during the interview. Practicing these questions will also assist you in being better prepared.
Written by William Swansen on October 25th, 2021
Answer Example
"ISAKMP defines the procedures used in a VPN. These include authenticating a peer attempting to communicate, creating and managing Security Associations (SA), key generation techniques, and mitigating denial of service and replay attacks. As a framework, ISAKMP typically utilizes IKE for key exchange. IKE is a two-phase protocol that generates a session key, protects the communication using algorithms, authenticates peers, and negotiates the second phase of the communication. In Phase 2, IKE establishes the SA. The three modes used by IKE include Main and Aggressive for Phase 1 and Quick for Phase 2. When Phase 2 negotiations are concluded, two unidirectional IPsec SAs are established, one for sending and one for receiving encrypted data."
Written by William Swansen on October 25th, 2021
Technical
23. Can you explain how the two IPsec protocol headers are used in a VPN?
How to Answer
While the nuances of VPN technology are transparent to the users and business leaders, people working in the IT department and managing the technology must be intimately familiar with all the technology's protocols, processes, and procedures. This is why most questions you will be asked during an interview will focus on the technology, specifics about how it works, and the protocols it employs. Interviewers use these questions to confirm your qualifications for the job and see if your knowledge aligns with the operations of their IT department.
Written by William Swansen on October 25th, 2021
Answer Example
"There are two types of IPsec protocol headers: Encapsulating Security Payload (ESP) and Authentication Header (AH). ESP is an IP-based protocol that uses port 50 to transmit data between IPsec peers. ESP is used to protect the information's authenticity, confidentiality, and integrity and provides anti-replay protection. The only issue is that ESP does not protect the outer IP header and may expose the user's IP address. AH is also an IP-based protocol that uses port 51 for communication between IPsec peers. AH does protect the IP header. It is used to secure the integrity and authenticity of the data but does not protect confidentiality. It also provides anti-replay protection."
Written by William Swansen on October 25th, 2021
Technical
24. Can you explain the differences between transport and tunnel mode data transmission?
How to Answer
As a VPN systems specialist, you are expected to have in-depth technical knowledge across VPN topics and the entire spectrum of network technology. When preparing for an interview, you should review the concepts, terminology, processes, and practices used to transport data across a computer network. Practicing questions like these will help you be better prepared for the interview and sound more professional.
Written by William Swansen on October 25th, 2021
Answer Example
"There are two types of data transmission modes in a network. The first is tunnel mode. Tunnel mode transports and protects data in network-to-network or site-to-site situations. It encapsulates the entire IP packet, including the data, the original IP header, and a new IP header. It also protects the user data. Transport mode is the second method for sending data across the network. This mode protects the data in host-to-host or end-to-end situations. In transport mode, IPsec protects the data in the original IP datagram by excluding the IP header, thereby only protecting the upper-layer protocols of IP payload."
Written by William Swansen on October 25th, 2021
Technical
25. What are symmetric and asymmetric encryption, and how is each used?
How to Answer
People who are in the network security industry should be familiar with the terminology used in this practice. They should also know the difference between terms and processes that are similar but differ from each other. This is an example of this type of question. Since this is a relatively basic question and can easily be answered by anybody with any knowledge of this topic, you should not spend a lot of time defining and describing these terms.
Written by William Swansen on October 25th, 2021
Answer Example
"Encryption is the process of changing the format of a digital message to protect it from being read by an unauthorized user. Symmetric encryption encrypts the data using a key and decrypting the message using the same key. This is easy to implement and creates little additional overhead but is easy to penetrate. It also requires a safe method to transfer the encryption key from the sender to the receiver. Asymmetric encryption is based on public and private key encryption techniques. It employs different keys to encrypt and decrypt the message. While it is more secure than symmetric encryption, it has more overhead and therefore is slower."
Written by William Swansen on October 25th, 2021
Technical
26. Can you discuss the differences between authentication, confidentiality, and integrity in the context of VPNs and network security?
How to Answer
Knowing the terminology used in this profession and discussing it is a basic qualification for anybody applying for a role involving managing a VPN. Interviewers will ask this type of question to qualify your expertise in this area and validate that you have experience working with VPNs. The easiest way to respond to this type of question is to define each of the terms and point out any differences from the other terms.
Written by William Swansen on October 25th, 2021
Answer Example
"Authentication verifies that a packet received was actually sent from the sender. It also verifies the authenticity of the sender. Some of the methods used for authentication include a pre-shared key and digital certificates. Integrity is the process of ensuring that the packet contents have not been altered during transmission by a man-in-middle attack. This is done with a hashing algorithm, using protocols such as MD5 or SHA. Confidentiality is the process of encoding the message content through encryption so that data is not disclosed to unauthorized parties. Some of the encryption algorithms used to accomplish this include Data Encryption Standard (DES,) Triple-DES (3DES,) and Advanced Encryption Standard (AES)."
Written by William Swansen on October 25th, 2021
Technical
27. What are some of an organization's security vulnerabilities that a VPN will address?
How to Answer
The organization's key reason to look for a VPN system specialist is to address its security vulnerabilities. Although it seems like an obvious question, the interviewer is probably trying to uncover your understanding of what a VPN does and whether the vulnerabilities you identify align with those they are experiencing or are concerned about. When preparing for an interview, you should research the company as much as possible to understand which vulnerabilities will have the greatest impact on their business and what measures they have taken to address these. You can also research how other similar organizations have addressed these same issues and use this information when formulating your answer to this question.
Written by William Swansen on October 25th, 2021
Answer Example
"A VPN performs several functions to address the security vulnerabilities of an organization. It protects user communications' privacy and indirectly provides an authentication mechanism for gateways, network devices, and authorized users. Privacy is critical to every business, its employees, and customers. This impacts what you discuss electronically and how much it is worth to someone else. Authentication is a side effect, even without IPsec. This prevents bad actors from impersonating an authorized user and gaining access to the network. It all comes down to the risk, which is proportional to the sensitivity of the information you are transmitting. The threats and vulnerabilities are out there. It is the function of the VPN to prevent them from impacting the organization's operations and reputation. It is my experience that while people may understand the value of the information they have, they may not accurately understand the risk of losing or compromising it."
Written by William Swansen on October 25th, 2021
Technical
28. What are some of the performance issues raised by the use of a VPN?
How to Answer
Every technology involves a tradeoff. Even though VPNs are highly recommended to protect an organization's information and provide Network Security, they impact the network's performance and the applications used by the end-users. Discussing this and recommending a balance between security and performance is a critical skill any VPN system specialist should have.
Written by William Swansen on October 25th, 2021
Answer Example
"Encryption performed by a VPN takes more bandwidth than sending data in the clear. This really is evident on mobile devices transmitting large amounts of data, such as a video file, over wireless connections. To mitigate this, VPNs, firewalls, and other server security systems should employ hardware crypto engines. With these, there are fewer performance issues without any compromise of the security of the information."
Written by William Swansen on October 25th, 2021
Technical
29. What are some of the crypto-related best practices recommended in the operation of a VPN?
How to Answer
Today's organizations are painfully aware of the threats to their information and proprietary data from malicious organizations and hackers. Business leaders may not understand the technology, but they understand the need to protect their data and the role that cryptography plays in this. When the interviewer asks this type of question, they are really asking for you to describe how you will protect their information utilizing technologies like crypto, VPN, and firewalls. When responding to their question, try to use non-technical language and avoid acronyms.
Written by William Swansen on October 25th, 2021
Answer Example
"Businesses that understand the need for encryption and how it protects the privacy of electronic documents also understand how data can be compromised and the need for the emergency recovery of the data. This can be done by saving an individual's private key information, encrypting it with a trusted third party's key, or saving all keys used to encrypt all documents. Whichever methodology is used, some mechanism is needed to recover encrypted files owned by an individual. Additionally, recovery of session keys used to encrypt a network connection is a law enforcement requirement. Therefore, VPNs must use the strongest available crypto compatible with the hardware on which it is being run. Weak cryptography should be completely avoided."
Written by William Swansen on October 25th, 2021
Technical
30. What are some of the firewall issues relevant to the selection and deployment of a VPN?
How to Answer
During an interview, the hiring manager will want to better understand your skills, competencies, and qualifications for this role. They will ask you specific questions about the duties for the position and the job you will be performing. Your answer should be based on your previous experience, education, and understanding of the job you are interviewing for. Assuming you are well qualified for the role, you should have no problem answering this type of question.
Written by William Swansen on October 25th, 2021
Answer Example
"It is critically important that VPNs integrate well with existing firewalls and that the two technologies complement each other. The issues I examine include the perimeter security and whether the firewall will provide the option of adding a VPN to the network, with or without trust. For example, I would configure the VPN to encrypt all the sessions between the firewall and the clients. Anything that isn't encrypted should bump up against and be stopped by the firewall. If I were to connect to the network from an external source, I want it to function as a private connection (encrypted), so it looks and feels like a virtual inside connection, just as if I was sitting in my office."
Written by William Swansen on October 25th, 2021