Cisco Network Consulting Engineer Interview Questions & Answers
1. Do you have experience managing heterogeneous networks that support both Linux and Windows?
How to Answer
While some companies elect to standardize on a single operating system across their entire network, larger enterprise companies like Cisco have IT environments consisting of heterogeneous equipment from a variety of manufacturers running different operating systems. The most common of these are Linux and Windows. As a qualified Network Consulting engineer, you should be familiar with both of these operating systems and be able to manage equipment on the network that runs them. You can state a preference for one or the other if you're confident that Cisco also has the same preference.
Answer Example
"Contemporary IT environments like Cisco's consist of a heterogeneous mix of different equipment and computer protocols. The most common of these are Linux and Windows. Therefore, as a Network Consulting engineer, I have to be proficient in both of these operating systems and be able to manage nodes on the network that run these."
2. What is a private IP address, and when would you use this if hired by Cisco?
How to Answer
As a network consulting engineer interview with Cisco progresses, the questions will become more complex and in-depth. This indicates that the Cisco interviewer is gaining confidence in your capabilities and is willing to explore your background in more detail. Regardless of the complexity of the technical or operational questions you are asked, continue to keep your answers brief and to the point. The interviewer will ask follow-up questions if they need more information or if the topic is critical to the organization's operations.
Answer Example
"Private IP addresses are used to identify user nodes on Cisco's internal networks, also known as intranets. These maintain the anonymity of the Cisco users to anyone outside of the organization. When users need to transmit data across the Internet, their addresses are translated into public IP addresses using NAT protocols. I use private IP addresses to keep internal user addresses secure. I also sometimes use them when I need to duplicate IP addresses on separate networks which do not see each other except when connected over the Internet."
3. What is a common way hackers attempt to shut down an organization's network?
How to Answer
One of the key functions network consulting engineers perform is ensuring that the company's network is kept secure and always available to authorized users. This requires network consulting engineers to be familiar with various threats hackers use to penetrate the network or shut it down. A Cisco interviewer will ask you about your knowledge of these threats to confirm that you know how to either prevent or remediate them. Since these threats are continually evolving, you may also be asked how you maintain your knowledge of these and stay on top of new ways hackers can infiltrate a network.
Answer Example
"One of the more common ways bad actors may attempt to shut down Cisco's network infrastructure is through Denial-of-Service attacks, also known as DoS. These types of attacks occur when hackers flood the network with a high number of requests. These requests overload the servers and prevent them from processing legitimate network traffic from authorized users. The key to remediate Denial-of-Service attacks against Cisco is to quickly identify them and route the traffic they are creating outside of the network. I also employ preventive measures such as firewalls and robust user authentication to prevent DoS attacks from occurring."
4. Can you describe some of the ways you would secure a Cisco computer network?
How to Answer
Interviewers will ask you about different ways you perform your job for two reasons. One is to confirm that you have the skillset and experience to do this work. The second reason is to see if your methodologies are similar to the ones currently used by the Cisco network consulting engineering team. Questions that inquire how you do your job are known as operational questions. The best way to respond to these is to break down the process into individual steps and explain them in simple, easy-to-understand terminology.
Answer Example
"There are several ways I can secure a Cisco computer network. It begins with user education and ensuring that the Cisco users know the importance of keeping their passwords secure and updating them frequently. Next, I install strong authentication software which ensures that only authorized users have access to the network. I also use methodologies including antivirus programs, firewalls, and VPN technology. Together, all of these steps ensure that the network is safe and that the Cisco user information and company data will not be compromised."
5. What is a protocol you would use to send data from one network to another?
How to Answer
This is a different format of a technical question. Rather than provide you with a term and ask you to define it and describe its use, the Cisco interviewer asks you about the protocol you would use to perform a specific function on the network. There is no standard format for technical questions the interviewer will ask you. By asking you how you would perform a specific function, they are confirming that you have experience in this area and have done this in one of your past positions.
Answer Example
"When transmitting data between networks, I typically use routing information protocol, or RIP. This is the most efficient way to manage routing data. The protocol broadcasts its routing table to all the other routers on the network. The appropriate router then identifies itself, and the information is transmitted to it. It may take several hops between different routers for the information to reach its ultimate destination."
6. Are you familiar with anonymous FTP, and can you provide the use case for it?
How to Answer
The Cisco interviewer will ask you about different technologies used in networking. Some of these questions address the technologies Cisco currently uses or is considering. Others may be general questions to explore your knowledge. When responding to technical questions, keep your answers brief and to the point. Also, be prepared for follow-up questions which the interviewer will use to explore the topic in more detail.
Answer Example
"Anonymous FTP grants a user access to files on public servers. Users are not required to identify themselves to access the files. A typical use case involves forms or information users need from public agencies such as the DMV, IRA, or other governmental entities. Cisco can also enable anonymous FTP for their clients, partners, or employees."
7. Can you describe Network Address Translation, or NAT, and the function it provides?
How to Answer
The field of networking involves a great number of different protocols used to transmit data between computer nodes. Each protocol has a specific purpose. Used properly, the protocols ensure that the data arrives at the intended destination as quickly as possible, intact, without being corrupted or intercepted. You should review common network protocols before an interview for a Cisco network consulting engineer's job to be familiar with these. Practicing questions like this one will also help you formulate your answers to the Cisco interviewer's question during the interview.
Answer Example
"Network Address Translation, or NAT, is a protocol that enables several computers on a single network to share one connection to the internet. NAT collects internet requests from individual nodes through a device such as a router and sends them to the internet. NAT converts the private IP address from each node into a public IP address so that the internet will know where to respond with the Cisco user's information. NAT routes the information to the individual user through their private IP address."
8. What information is collected when IP access list logging is enabled?
How to Answer
This is an example of a basic network technology question. During the interview for a network consulting engineer's role at Cisco, you'll be asked many technical and operational questions. The Cisco interviewer can ask difficult or basic questions at different times during the interview. You should be prepared for these at any time. No two interviewers are alike, so having a general knowledge of network principles, techniques, terminology, processes, and procedures will help you answer any questions you are presented with during the interview.
Answer Example
"IP access list logging provides the ability to log information about the packets that are permitted or denied by a standard IP access list. If a packet matches the access list, its information is sent to the device console. Information collected about the packet includes its source address, protocol, the port where it originated, the destination address, its access list number, and the destination port."
9. Who developed NetFlow, and how is it used?
How to Answer
Network technologies evolved as the need to connect computers grew, and the speed, distance, and the number of nodes on the network increased. Knowing the background of some of the technologies you use and who developed them not only helps you manage the network, it shows that you have an interest in the industry and your profession beyond just day-to-day activities. This will impress the Cisco interviewer and differentiate you from the other candidates applying for this job. Additionally, since NetFlow was developed by Cisco, you are expected to know this.
Answer Example
"NetFlow is an open but proprietary network protocol created by Cisco Systems. It collects active IP network traffic as it flows in or out of an interface. Data collected by NetFlow is analyzed to understand network traffic flow and the volume of data transiting the network. I use NetFlow protocol as a network traffic analyzer to determine the point of origin of data packets, their destination, the overall volume on the network, and the paths the data takes."
10. What is VMPS?
How to Answer
As the interview with Cisco progresses, the questions will become more challenging. This indicates that the interviewer is gaining confidence in your capabilities and is willing to test your qualifications in more detail. It would be best if you continued to answer the questions directly and to the point using simple and easy-to-understand language. As with any question, be prepared for a follow-up.
Answer Example
"VMPS stands for VLAN Membership Policy Server. A VLAN is a virtual local area network whose domain is partitioned and isolated in a computer network at the data link layer. VMPS makes it possible to use a client/server architecture to manage dynamic VLAN based on the MAC addresses of the nodes. When someone connects to a port on the network, a switch connects it to the VMPS to verify that this MAC address can be connected to the port."
11. How do you use SPAN and RSPAN to manage network traffic?
How to Answer
While this question could stand alone, it may also be a follow-up to a previous question that asked you about the tools you use to manage network traffic. Interviewers like the ones at Cisco will ask follow-up questions immediately after the initial question or later in the interview. If asked immediately, they want more information about the topic. If asked later in the interview, the interviewer is looking to confirm that you're consistent in your answers during the interview. In either case, answering factually and truthfully will provide the interviewer with the information they seek and confirm that you're consistent in your answers.
Answer Example
"SPAN, which stands for Switched Port Analyzer, and RSPAN, which is Remote Switched Port Analyzer, are both tools that enable me to monitor traffic flowing from one port to another. The tools copy ethernet frames passing through switch ports. SPAN and RSPAN don't analyze these copied frames; they send frames from a specific port to a network analyzer. I use these tools to help analyze and measure traffic on the net and make any adjustments to increase the performance."
12. What do the acronyms TACACS and RADIUS stand for, and how are they used in a network environment?
How to Answer
This is a classic technical question. It first asks you to define two terms used in your profession and then to discuss their function. This is the same format you should use when responding to the question. Keep your answer brief and to the point, and anticipate a follow-up question that the interviewer will use to delve deeper into the topic. If they ask a follow-up question, it indicates that the topic may be important to their operations.
Answer Example
"Terminal Access Controller Access-Control System, or TACACS, is a remote authentication protocol used to communicate with an authentication server commonly used in UNIX networks. TACACS allows a remote access server to communicate with an authentication server to determine if the user is authorized to access the network. Remote Authentication Dial-In User Service (RADIUS) is also a protocol for controlling access to a network. Internet service providers and companies commonly use RADIUS to manage access to internal networks across several technologies, including modem, DSL, wireless, and VPNs."
13. Can you discuss some reasons the networking industry uses a layered transport model?
How to Answer
This is an interesting question. Most networking professionals will understand the layered transport model and can name each layer and its purpose. However, many may not be able to discuss why the model was developed and what led to this. While having a historical perspective of your industry and profession doesn't help you with your day-to-day operations, it will demonstrate your qualifications in the field and could differentiate you from other candidates.
Answer Example
"The main reason the network industry uses a layered transport model is that it facilitates the management of each function in the movement of information across the network. It also facilitates systematic troubleshooting. This is because the layered model clarifies what general function is associated with which layer. Also, changes in one layer can occur without changing other layers, thereby allowing the network engineers to fix issues associated with one of the layers and to optimize the performance of the network by tweaking each layer."
14. What are some of the things you consider when designing an enterprise network?
How to Answer
The Cisco interviewer will ask you this question not to understand your technical expertise but rather your experience in the network management field. While even novice network engineers can talk about network principles and fundamentals, only experienced network consulting engineers can discuss how to efficiently design and configure a complex network topology. Keep in mind that you're not being asked to design a network but only to talk about the principles you use when doing so. Keep your answer concise and anticipate follow-up questions from the interviewer.
Answer Example
"Some of the things I consider when beginning to design a complex enterprise network are the number of nodes or users, the applications that the users will be running, the topology of the network, and how many buildings, floors, and offices will be included, and the need to provide network access outside of the main campus. I consider the security requirements, whether the organization needs an extranet, the performance expectations of each department, and finally, the budget. Once I understand all of these factors, I can begin designing the network which will result in maximum performance at the least possible cost."
15. What are the tools you use to troubleshoot network issues?
How to Answer
A Cisco interviewer will ask you about the tools you use to manage the network to confirm your qualifications and to also understand if the tools you prefer are the same ones the Cisco team currently uses. It is advisable to thoroughly research the organization before the interview to understand how they manage their network environment. The network management tools may be mentioned in the job description or on Cisco's website. You can also learn about this by speaking with current and former Cisco employees of the company's network operations team.
Answer Example
"The tools I use to troubleshoot and manage a network are a combination of command-line utilities and commercially available network management suites. The command-line utilities include Ping to check the speed of connections, Tracert, a utility that lists the probable hops to a destination address, Ipconfig which reports the IPv4 and IPv6 addresses, subnets, and default gateways, Netstat, which displays active connections, and Nslookup, a tool that gives you DNS server diagnostics. I also prefer commercial network management suites, including SolarWinds Port Scanner, N-able RMM, Paessler Network Troubleshooting, and Wireshark."
16. When working to create a safe network environment, which security procedures do you recommend?
How to Answer
One of the key qualifications a network consulting engineer brings to an organization such as Cisco is securing their networks and the data transmitted across them. When interviewing for this role, you'll be asked about the processes and procedures you use to accomplish this objective. Your answer can include standard industry solutions and unique approaches you have developed based on your years of experience. Try to make your answer relevant to Cisco's operations, which you should be familiar with based on your research before coming to the interview.
Answer Example
"I have several tools and processes available to help me maintain the security of all the networks I am responsible for. These include firewalls, VPNs, strict control of access and user authentication, specific security software products, and ensuring everything is kept up to date, and closely monitoring intrusions, spyware, and hackers. However, the most effective tool I have is making sure that the users are well-educated and aware of how they can prevent security breaches by protecting their passwords, not downloading unauthorized software to Cisco's network, and other similar practices."
17. What is the most efficient routing protocol you have implemented?
How to Answer
While this question seems extremely basic, discussing networking fundamentals is exactly what a company is looking for in a new hire. The Cisco interviewer expects you to respond with an explanation of the basic features of a router, its function, and how you use it. Keep your answer direct and to the point, using non-technical language. You should also be prepared for a follow-up question which the interviewer will use to dive deeper into the topic.
Answer Example
"A router is an intelligent switch which directs network traffic to and from nodes on the network. Efficient transmission of information is based on the routing protocol, which selects the best routes between any two nodes. Three typical types of routing protocol are Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Interior Gateway Protocol (IGP). I prefer OSPF, which is based on the Shortest Path First (SPF) algorithm; it calculates the shortest path to each node and is, therefore, the most efficient."
18. What steps do you take to improve the efficiency of a network?
How to Answer
After initially designing a network infrastructure, network consulting engineers are continually challenged to maintain its performance and increase its efficiency. This is especially true as the network grows, adding users and nodes. The interviewer wants to make sure that you can continue to maintain and improve Cisco's network's performance. This can be done using several different techniques involving hardware, software, and traffic management solutions.
Answer Example
"Improving the performance and efficiency of the network is something I spend most of my time on. I am always concerned about the network providing users with the resources they need to do their jobs effectively and efficiently. Some of the methods I use to maintain the efficiency of the network include ensuring that the hardware is up to date, using traffic monitoring tools to understand the network's performance and how it is being used, and employing new software solutions to increase the network's speed. Of these, monitoring and redirecting the traffic is the most effective tool I have. I increase efficiencies by segmenting portions of the network and redirecting traffic to the least used network segments."
19. As you know, with more people coming online around the globe, available network addresses are disappearing. How do you feel about this issue?
How to Answer
This is a general question that is asking your opinion on an industry issue. While it may not test your qualifications for this role, it does provide the Cisco interviewer with information about how closely you follow industry events and whether you have an opinion about a critical issue it is facing. If you are familiar with the issue, feel free to give your opinion as long as you can substantiate it. If you're unfamiliar with the issue they are asking about, acknowledge this, then describe how you would go about learning more about it.
Answer Example
"I am following the issue of the decreasing availability of network addresses, and I am concerned about this. When network technology was first developed, no one could have anticipated how broadly it would be adapted and how many addresses would be required across the globe. I believe that we as an industry can address this in several ways. The first is to ensure that all the currently allocated addresses are in use, and if not, to reallocate them for new users. I also believe we can work on technology that would enable the existing addresses to be used by multiple users with techniques such as machine code and multiplexing algorithms. I understand that Cisco, along with some of the international network standards organizations, is already working on these types of solutions."
20. How do you explain complex technical ideas to coworkers and clients who don't have the same technical knowledge as you to ensure they understand what you're describing?
How to Answer
It is important to understand that information technology is simply a tool Cisco uses to accomplish its business objectives. The IT systems, including the network systems, must be designed to fulfill the other departments' needs. To do this, you need to collaborate and communicate with the other departments. When discussing information technology with non-technical users, use simple, easy-to-understand language to explain the functions and benefits of the solutions you provide. You can give the interviewer an example of this to illustrate how you do it.
Answer Example
"I collaborate closely with the heads of the departments across the organization to ensure that the network systems are designed to provide them the services they need to accomplish their jobs. When discussing my solutions with other departments, I keep the conversation simple and easy to understand. I use very few acronyms or technical terms, and I present the functions and benefits of the solutions in the context of the business problems they solve. I am patient with their questions and go to great lengths to make sure they understand how the network functions, the issues they may encounter, and the resources I can provide them."
21. How do you scale networks so they can accommodate the evolving needs of an organization like Cisco?
How to Answer
Designing networks that scale as the organization grows is a key qualification for a talented network consulting engineer. When the interviewer at Cisco asks you about this, you should have a clear answer as to how you design networks that are cost-effective for the organization's current needs that can scale easily over time. Your answer can include solutions such as scalable technology, systems, and software that are easily upgraded or expanded, providing standby cabling solutions, designing data centers for growth, and utilizing third-party and service provider resources.
Answer Example
"Whenever I design a network solution, I anticipate the growth prospects of the organization and the scalability of the network. Elements I use to enable the system to grow to include specifying hardware and software that is easily expanded or updated, provisioning dark fiber that can be brought online as Cisco adds more users, provisioning data centers with additional capacity, and other similar measures. I also maintain relationships with third-party providers and cloud service organizations. These enable me to provision or de-provision users on-demand or permanently extend the organization's capabilities."
22. Walk me through the process you use to troubleshoot a network when you are not getting the performance you expect?
How to Answer
This question provides the Cisco interviewer with a description of how you approach solving a complex problem. They are less interested in you solving the problem than learning about the process you use. When walking the interviewer through a process, you should break it down into individual, easy-to-understand steps describing each in simple language. You can use a combination of unique techniques as well as industry-standard practices to resolve the issue. Also, include a brief description of what you would do if you could not reach a solution.
Answer Example
"When troubleshooting a network issue, the first thing I do is eliminate the most obvious and simple to resolve issues. These could be disconnected cables, power to the systems, user logins, or other simple issues. If these don't resolve the issue, I deploy hardware and software diagnostic tools to make sure the network is functioning properly. If these identify the issue, I quickly resolve it by updating the software or replacing the hardware. If I cannot do this, I open a severe case trouble ticket to escalate the issue. In the meantime, I provide the user with an alternate method to access the network so they can continue to work on their projects."
23. Can you describe the largest network you have engineered and some of the design elements?
How to Answer
This question allows the Cisco interviewer to determine whether you have experience with networks similar to theirs, even if your experience isn't in the same industry or with the technology used by Cisco. They are simply looking for general familiarity with the challenges and requirements that come with a company of their size.
Answer Example
"I have created and implemented networks for a wide range of organizations, including SMBs to Fortune 500s, like Cisco. The networks I developed have supported single locations and global organizations, using a mix of on-premises solutions and cloud-based resources. The largest of these was for a global pharmaceutical firm with research and manufacturing operations here in the U.S., Europe, and Asia. In total, there were ten main locations with 75 individual buildings and 50,000 users. I was primarily responsible for supporting the U.S. locations. Still, I collaborated with my peers from around the world to ensure that the entire network was able to communicate with each other and utilized the same technologies and protocols."
24. Please draw an illustration of a typical network topography and explain the details to me.
How to Answer
A key responsibility of a network consulting engineer is creating the network designs for the organization. The Cisco interviewer expects you to be able to sketch out a rough network diagram and explain your rationale for the topography. When asked to do this, keep your diagram simple, using easy-to-understand illustrations and little to no text. Focus on the explanation to demonstrate your knowledge of network design concepts and elements.
Answer Example
"As you can see from my diagram, this is a network topology for a medium-sized organization with several departments. I've used a combination of switches, hubs, and routers to segment the network and isolate several of the user groups. This allows me to direct the network traffic more granularly, thereby improving the performance of the network. I've also designed in firewalls and VPNs to prevent unauthorized intrusions while providing the organization's users secure access to the Internet."
25. What safeguards do you design into a network to limit unauthorized intrusions and data loss?
How to Answer
Second only to providing network availability and access to online resources is the need to secure the information transported across the company's network infrastructure. As a Cisco network consulting engineer, you're expected to be able to describe how you accomplish securing the company's proprietary information and maintaining the security of the network. The interviewer at Cisco wants to feel confident that you're capable of doing this. They may also be looking for innovations you can bring to the organization to help them improve their current security practices.
Answer Example
"One of my primary responsibilities as a network consulting engineer is to secure the information used by the organization. I do this in several ways. These include strict user access and authentication, technologies including VPNs and firewalls, constant monitoring of the network using automated tools, and installing software updates and patches to address evolving security concerns. I also take time to educate the end-users of best practices for securing their login information and preventing unauthorized access from hackers, spyware, and software worms."
26. What is your experience with collaborating with development teams and business stakeholders when deploying network resources?
How to Answer
Collaborations across technology teams and other departments in the organization are common in the business world. Network resources significantly impact Cisco's operations, so they need to be available and match the needs of each department. Your answer to this question should make the interviewer feel confident in your ability to communicate and work with multiple people with different backgrounds and technical skills from across the entire organization.
Answer Example
"Cisco's network infrastructure is simply a tool that users and departments across the organization use to accomplish their business objectives. I recognize this and seek to develop and manage network infrastructures that support the company's needs. To do this, I would collaborate closely with the business leaders in each department within Cisco. When communicating with them, I will use clear and non-technical terms to describe the resources I can provide and how they function. I've also taken some business courses, so I understand the functions of each department within the organization. This helps me design network services to support these."
27. How do you stay informed about developments and advances in network technologies?
How to Answer
As a Cisco Network Consulting Engineer, you are expected to be current on the most recent developments in networking technology, techniques, and processes. This question tests your ability to stay up to date with advancements in network practices and technologies. The Cisco interviewer seeks to understand if you have the initiative to continually learn about the latest technology. In addition, you should be able to describe specific processes and resources you use to accomplish this.
Answer Example
"Our industry moves at a rapid pace, and there are technological advances almost every day. To stay on top of these, I use a variety of methods. These include vendor websites, technology blogs, and online training. I participate in local network engineering and end-user groups and attend industry trade shows and seminars. I also spend a lot of time discussing network developments and issues with my peers in my organizations."
28. What has been the most complex network system you have designed and installed?
How to Answer
Cisco interviewers can usually tell from your resume the depth of your experience and knowledge. What they can't tell from the resume is the scope of these. Describing the largest or most complex network system you have worked on provides this information. It also helps the interviewer understand whether you're qualified to work in Cisco's network environment and have the experience to address the issues you're likely to encounter based on the complexity of their network infrastructure.
Answer Example
"The most complex network system I have supported was for a global manufacturing company. My team and I supported sites in seven different countries located on three continents. The systems included LANs, WANs, and individual remote users connecting to the company network via the Internet. Issues we dealt with included connectivity, access to local service providers, variations in power and electrical systems, the need to support systems both locally and remotely, and the challenges of working across time zones and with users who spoke different native languages. We developed specific systems and processes to address all of these and maintained a five-nines network uptime across the entire system."
29. What situations would warrant an after-hours visit to a client location by you or a member of the Cisco network support team?
How to Answer
In today's connected world, most networking issues can be resolved online and remotely. However, some issues require an onsite visit to manually reset or replace the hardware or software at the end-user location. Qualified network consulting engineers will recognize when an onsite visit is required. Minimizing these will reduce the cost of support and the resources needed to support remote users. It will also ensure that remote users have access to the network to do their jobs.
Answer Example
"As you might expect, I always try to minimize the need to send a technician onsite to a remote location. Onsite visits are costly, extend the downtime for the end-user, and reduce the resources I have available to resolve other issues. When the remote user calls with a technical issue, my team and I use a hierarchical approach to resolve the issue. We use several different online tests to identify the root cause and then use procedures we can execute over the network to try to resolve it. Only when all of these have failed would we send a Cisco technician onsite. When dispatched, the Cisco technician will be equipped with all the hardware and software resources we feel they will need to quickly resolve the issue."
30. Do you have experience creating efficient end-user support systems, and if so, can you describe your approach to this?
How to Answer
In addition to designing and managing Computer Networks, one of the roles of a Cisco network consulting engineer is to support the company's end-users. The interviewer at Cisco seeks to understand your experience with this and how you can improve the help desk and support system they already have. The answer they're looking for includes anticipating the training needs of the organization, designing systems Cisco end-users can use to self-support, and creating resources the network support team can use to provide answers to the end-users and resolve issues they may have.
Answer Example
"I have a great deal of experience creating end-user support systems for network issues. I always start with training and making sure that the end-users are knowledgeable about how a network functions and some of the minor problems they can fix themselves. I supplement this by creating online resources they can access, containing FAQs and step-by-step tutorials for fixing minor issues. I have also created effective help desks and support systems used by the network support team to address end-user issues. These include informational resources they can use to quickly identify and resolve network issues, as well as a robust ticket system to log, track, and resolve support issues."