All 113 questions

  1. What is HTTPS, and how does it differ from HTTP on the wire?

    Asked in 8 of 337 interviews · last asked Sep 21 · Concept · Junior

    Show answer

    HTTPS is HTTP protected by TLS. Unlike plain HTTP, it sends HTTP headers and bodies as encrypted data. A TLS handshake sets up encryption and normally checks the server's certificate. This protects against reading or changing traffic in transit.

    • HTTP uses port 80 by default; HTTPS uses port 443.
    • The client checks that the server certificate is trusted and matches the requested hostname.
    • IP addresses remain visible, and the hostname may still be exposed.
    • HTTP/1.1 and HTTP/2 use TLS over TCP for HTTPS; HTTP/3 uses QUIC with integrated TLS over UDP.

    What the interviewer checks: The interviewer checks whether you understand encryption, server identity checks, and what changes on the wire.

    Other ways it was asked
    • “What is the difference between HTTP and HTTPS?”
    • “What is HTTPS?”
    • “What's the difference between HTTP and HTTPS, and what actually happens differently on the wire?”

  2. What is a VPN, and what is it used for?

    Asked in 5 of 337 interviews · last asked Sep 2 · Concept · Junior

    Show answer

    A VPN (Virtual Private Network) creates a private connection over a shared network, usually through an encrypted tunnel. It is used to access company resources remotely, connect office networks, and protect traffic on public Wi-Fi. Depending on its settings, it carries all traffic or only selected traffic.

    • Remote-access VPNs connect users to a network; site-to-site VPNs connect networks.
    • VPN encryption protects traffic between the device or network and the VPN gateway.
    • A VPN can hide your public IP address from websites, but it does not guarantee anonymity.

    What the interviewer checks: The interviewer checks whether you understand VPN tunnels, their main uses, and their privacy limits.

    Other ways it was asked
    • “What are VPNs, and what are they used for?”
    • “What is a VPN, and how does it work?”
    • “What is a VPN?”

  3. How does a browser establish a secure connection using the TLS handshake?

    Asked in 3 of 337 interviews · last asked Oct 13 · Concept · Junior

    Other ways it was asked
    • “How does a browser establish a secure connection?”
    • “How does the TLS handshake work?”
    • “What do you know about the TLS handshake model?”

  4. When a VPN user can connect but can’t reach any internal subnets, how do you distinguish routing issues from DNS issues and split-tunnel policy problems?

    Asked in 2 of 337 interviews · last asked Sep 3 · Scenario · Mid-level

    Other ways it was asked
    • “A user connects successfully, gets an assigned VPN IP, but cannot reach any internal subnets. What would you check first regarding routes, DNS, and split tunnel versus full tunnel policy?”

  5. What is RDP used for?

    Asked in 2 of 337 interviews · last asked Sep 29 · Concept · Junior

    Other ways it was asked
    • “What is RDP, and what is it used for?”

  6. What is the port number for SSH?

    Asked in 2 of 337 interviews · last asked Sep 19 · Concept · Junior

    Other ways it was asked
    • “What port does SSH use by default?”

  7. How do you send credentials in the HTTP Basic Authentication header?

    Asked once · last asked Jul 24 · Concept · Junior

    Other ways it was asked
    • “How do you send credentials using HTTP Basic Authentication in an HTTP request?”
    • “How do you send a username and password in the headers for HTTP Basic Authentication?”
    • “How do you use HTTP Basic Authentication?”

  8. How would you determine how many ViPNet coordinators an organization needs?

    Asked once · last asked Aug 20 · Scenario · Mid-level

    Other ways it was asked
    • “How many ViPNet coordinators would an organization need?”
    • “How does the number of employees affect the number of ViPNet coordinators an organization needs?”

  9. What is SIP ALG (also called SIP helper), and how can it affect SIP traffic over a VPN?

    Asked once · last asked Feb 17 · Concept · Mid-level

  10. How do you configure or troubleshoot DMVPN?

    Asked once · last asked Feb 24 · Tooling · Mid-level

  11. What is the difference between DMVPN Phase 2 and Phase 3?

    Asked once · last asked Feb 24 · Concept · Mid-level

  12. How would you troubleshoot ZPA or ZIA using the Zscaler console and user logs?

    Asked once · last asked Feb 24 · Tooling · Mid-level

  13. What are the main architectural differences between Cisco ASA and Palo Alto firewalls?

    Asked once · last asked Feb 27 · Concept · Mid-level

    Other ways it was asked
    • “What are the differences between NAT policies on Cisco ASA and Palo Alto firewalls?”

  14. For an Internet-facing FortiGate and a new FTP server in the DMZ that must be accessible from the Internet, what questions would you ask, and how would you approach the firewall configuration?

    Asked once · last asked Mar 6 · Scenario · Senior

  15. How would you fail over a Palo Alto firewall from active to passive? Walk me through the steps.

    Asked once · last asked Mar 11 · Tooling · Mid-level

  16. When establishing a BGP connection between two endpoints with a firewall in between, what needs to be allowed for the connection to come up?

    Asked once · last asked Mar 20 · Scenario · Mid-level

  17. What security header recommendations would you give backend developers to improve a web application's security?

    Asked once · last asked Mar 20 · Scenario · Mid-level

  18. How do you use Cisco ISE in network operations?

    Asked once · last asked Mar 23 · Tooling · Mid-level

  19. What difference do you see between Cisco ASA and Check Point?

    Asked once · last asked Apr 6 · Concept · Mid-level

  20. If we host websites internally for external users, what security checks would you make, and how would you design the traffic flow from our network to those users?

    Asked once · last asked Apr 6 · Design · Senior

  21. What is DMVPN, and when would you use it in a network?

    Asked once · last asked Apr 7 · Concept · Mid-level

  22. Can you explain the two phases of an IPsec tunnel?

    Asked once · last asked Apr 7 · Concept · Mid-level

  23. If an IPsec tunnel fails to establish or a previously working tunnel goes down, what would you check first, and what could cause the problem?

    Asked once · last asked Apr 7 · Scenario · Mid-level

  24. What are the five elements you configure for IPsec Phase 1?

    Asked once · last asked Apr 7 · Concept · Mid-level

  25. What steps or elements do you configure for IPsec Phase 2?

    Asked once · last asked Apr 7 · Concept · Mid-level

  26. Explain the different Palo Alto firewall deployment modes, including how virtual systems isolate traffic and how they relate to VLANs, NAT, and legacy firewalls.

    Asked once · last asked Apr 13 · Concept · Mid-level

  27. What is IPsec, and how is it used to secure network communications?

    Asked once · last asked Apr 13 · Concept · Mid-level

  28. How is IPsec used in an SD-WAN deployment?

    Asked once · last asked Apr 13 · Concept · Mid-level

  29. How would you onboard a new FTD firewall to FMC?

    Asked once · last asked Apr 15 · Tooling · Mid-level

  30. Can you walk me through guest authentication, including where the captive portal is hosted and how a guest user is authenticated?

    Asked once · last asked Apr 15 · Concept · Mid-level

  31. What is the difference between 802.1X and RADIUS?

    Asked once · last asked Apr 15 · Concept · Mid-level

  32. How does a corporate SSID user connect, and what authentication method and flow are used?

    Asked once · last asked Apr 15 · Concept · Mid-level

  33. What are the main types of VPN, such as site-to-site and remote-access VPNs?

    Asked once · last asked Apr 15 · Concept · Junior

  34. What role does Cisco ISE play in RADIUS-based network access control?

    Asked once · last asked Apr 24 · Concept · Mid-level

  35. How can Cisco ISE support wireless and wired 802.1X access control, network access control, and posture assessment?

    Asked once · last asked Apr 24 · Concept · Mid-level

  36. Does EAP-TLS apply to domain-joined computers, and how do you provide wireless access for company-owned tablets or iPads that aren’t joined to the domain?

    Asked once · last asked Apr 24 · Scenario · Mid-level

  37. What are the two phases of a site-to-site VPN?

    Asked once · last asked Apr 27 · Concept · Mid-level

  38. What settings do you need to configure in a VPN client to establish a connection?

    Asked once · last asked May 8 · Tooling · Junior

  39. What are common VPN protocols, and how do they differ?

    Asked once · last asked May 8 · Concept · Mid-level

  40. Why might a connection be insecure even though it uses SSL?

    Asked once · last asked May 12 · Scenario · Mid-level

    Other ways it was asked
    • “Why is the connection not secure even though it uses SSL?”

  41. How would you create an inbound rule to allow HTTP traffic?

    Asked once · last asked May 13 · Scenario · Mid-level

  42. How can an external vendor reach a private subnet, and when would a public-facing endpoint be needed?

    Asked once · last asked May 21 · Scenario · Senior

  43. What is TLS, and what are the differences between TLS 1.1 and TLS 1.3, excluding TLS 1.2?

    Asked once · last asked May 27 · Concept · Mid-level

  44. How does a router or firewall block traffic, and how does it protect the network?

    Asked once · last asked Jun 8 · Concept · Junior

  45. If a user accesses https://google.com through a Palo Alto firewall, how does the firewall identify the destination, and can it block the access? If so, how?

    Asked once · last asked Jun 11 · Scenario · Mid-level

  46. How would you set up and manage a VPN network in AWS?

    Asked once · last asked Jun 15 · Tooling · Mid-level

  47. If the database connection string is correct, how would you check whether firewall rules, security rules, or database configuration are causing the connection problem?

    Asked once · last asked Jun 19 · Scenario · Mid-level

  48. How would you check network access and permissions when troubleshooting a database connection, including database ports and allowlist rules?

    Asked once · last asked Jun 19 · Scenario · Mid-level

  49. How would Wireshark help identify ARP spoofing on a network?

    Asked once · last asked Jun 20 · Tooling · Mid-level

  50. What is the difference between a stateful and a stateless firewall?

    Asked once · last asked Jun 20 · Concept · Mid-level

  51. How would you review firewall rules, configure VPNs, and troubleshoot network issues for a client site?

    Asked once · last asked Nov 13 · Scenario · Mid-level

  52. When you review firewall rules, what are you reviewing?

    Asked once · last asked Nov 13 · Concept · Mid-level

  53. What are the differences between client-to-client, client-to-firewall, and site-to-site VPNs?

    Asked once · last asked Nov 13 · Concept · Mid-level

  54. What are IPsec tunnels, and when would you use them?

    Asked once · last asked Nov 13 · Concept · Mid-level

  55. How do you configure a cluster using Fortinet devices?

    Asked once · last asked Jul 16 · Tooling · Mid-level

  56. What is the difference between split tunneling and full tunneling?

    Asked once · last asked Jul 3 · Concept · Mid-level

  57. How do you create a VPN tunnel?

    Asked once · last asked Jul 4 · Tooling · Junior

    Other ways it was asked
    • “How do you create an IPsec tunnel?”
    • “What commands do you use to create a VPN tunnel?”

  58. What is a TLS certificate, what does it contain, and who issues it?

    Asked once · last asked Jul 23 · Concept · Mid-level

    Other ways it was asked
    • “What is a certificate? What's inside a certificate and who issues it?”

  59. Why are self-signed certificates not trusted by browsers, while certificates from other certificate authorities are trusted?

    Asked once · last asked Jul 23 · Concept · Mid-level

  60. How does a browser verify trust in a certificate chain?

    Asked once · last asked Jul 23 · Concept · Mid-level

  61. Are credentials encrypted when using HTTP Basic Authentication?

    Asked once · last asked Jul 24 · Concept · Mid-level

  62. What security mechanisms are embedded in HTTPS?

    Asked once · last asked Jul 31 · Concept · Mid-level

  63. If a firewall is in the network path, where does it generally sit in relation to the NAT process?

    Asked once · last asked Aug 4 · Concept · Mid-level

  64. How do you route traffic to cloud security services such as SWG, CASB, and firewall as a service?

    Asked once · last asked Aug 4 · Concept · Senior

  65. How would you design a network security architecture for 400 branches, two data centers, Azure connectivity, and a remote workforce accessing services hosted in the data centers? What solution components would you consider?

    Asked once · last asked Aug 6 · Design · Senior

  66. How would you approach designing a SASE architecture, and what solution components would you consider?

    Asked once · last asked Aug 6 · Design · Senior

  67. Explain DNS tunneling.

    Asked once · last asked Aug 6 · Concept · Mid-level

  68. How do you handle content filtering and categorization when DNS queries and network traffic are encrypted?

    Asked once · last asked Aug 6 · Scenario · Senior

  69. Can you walk me through how key exchanges work to support TLS inspection?

    Asked once · last asked Aug 6 · Concept · Senior

  70. What steps would you take to secure a corporate network against external threats such as DDoS attacks and data breaches?

    Asked once · last asked Aug 11 · Scenario · Senior

  71. How might SASE affect a product portfolio that includes SD-WAN, ClearPass, and SRX, and what other products might be brought into it?

    Asked once · last asked Aug 13 · Scenario · Senior

  72. How would you set up and troubleshoot IPsec tunnels during a proof of concept, and explain overlay networking concepts on a whiteboard?

    Asked once · last asked Aug 17 · Scenario · Senior

  73. What are the specific things to check when troubleshooting a pair of IPsec tunnels over the public internet that are failing to come up?

    Asked once · last asked Aug 17 · Scenario · Senior

  74. How would you administer a complex Check Point environment?

    Asked once · last asked Aug 19 · Behavioral · Mid-level

    Other ways it was asked
    • “Walk me through one of the more complex Check Point environments that you’ve helped administer or managed.”

  75. How do high availability, clustering, and failover work in firewall environments?

    Asked once · last asked Aug 19 · Concept · Mid-level

  76. How would you manage firewall rule changes for a new application, including identifying required ports and access?

    Asked once · last asked Aug 19 · Scenario · Mid-level

  77. How would you troubleshoot an IPsec tunnel to a network fabric that is not coming up?

    Asked once · last asked Aug 19 · Scenario · Senior

  78. Can a user access a DMZ using only RDP, or are additional tools required?

    Asked once · last asked Aug 20 · Scenario · Mid-level

  79. How could a VPN help provide access to a 1C system?

    Asked once · last asked Aug 20 · Scenario · Mid-level

    Other ways it was asked
    • “How could a VPN help provide access to a 1C system in this scenario?”

  80. How would you design and size a ViPNet deployment for an organization?

    Asked once · last asked Aug 20 · Design · Mid-level

  81. How would you maintain connectivity if the VPN tunnel failed?

    Asked once · last asked Aug 20 · Scenario · Mid-level

  82. Does an IPsec tunnel natively support OSPF, or do you need an additional mechanism?

    Asked once · last asked Aug 26 · Concept · Senior

  83. In your mind, what are the key failure points for remote access architectures, and how do you design around them for the highest availability?

    Asked once · last asked Aug 27 · Design · Senior

    Other ways it was asked
    • “What other single points of failure can affect remote access architectures?”

  84. What is the difference between OTAA and ABP?

    Asked once · last asked Sep 2 · Concept · Mid-level

  85. What does a /32 route on a VPN client typically indicate, and how could it impact access to internal subnets?

    Asked once · last asked Sep 2 · Concept · Mid-level

  86. What factors do you consider when adding an object or a static route to a firewall?

    Asked once · last asked Sep 17 · Scenario · Mid-level

  87. Where would you place firewalls in a network, and what factors would guide their placement?

    Asked once · last asked Sep 18 · Design · Senior

  88. How would you determine how many firewalls a network needs?

    Asked once · last asked Sep 18 · Design · Senior

  89. In HTTPS, does the server need a certificate, or does the client need one as well?

    Asked once · last asked Sep 21 · Concept · Mid-level

  90. How would you secure authentication and authorization for real-time WebSocket connections?

    Asked once · last asked Sep 23 · Scenario · Mid-level

  91. What are SPF, DKIM, and DMARC for, and what happens to email when they are wrong?

    Asked once · last asked Oct 8 · Concept · Mid-level

  92. What is IEEE 802.1X, and how is it used for network access control?

    Asked once · last asked Oct 22 · Concept · Mid-level

  93. How do you create an inbound firewall rule?

    Asked once · last asked May 13 · Tooling · Junior

    Other ways it was asked
    • “How do you create an inbound rule?”
    • “How do you create a custom inbound rule?”

  94. Could you explain SSH?

    Asked once · last asked Feb 3 · Concept · Junior

  95. After the TCP and TLS handshakes are complete, what else may be required before a client can access data on an application server?

    Asked once · last asked Apr 13 · Scenario · Mid-level

  96. When do we use 802.1X?

    Asked once · last asked Apr 15 · Concept · Junior

  97. What interface types are available on Palo Alto firewalls? Can you name a few?

    Asked once · last asked Jun 11 · Concept · Junior

  98. What is a session key in a TLS connection?

    Asked once · last asked Jun 20 · Concept · Junior

  99. What does it mean that HTTPS is encrypted?

    Asked once · last asked Jul 23 · Concept · Junior

  100. How do you obtain a TLS certificate, and who issues it?

    Asked once · last asked Jul 23 · Concept · Junior

  101. Why does a browser trust a certificate issued by a certificate authority?

    Asked once · last asked Jul 23 · Concept · Mid-level

  102. What is TLS?

    Asked once · last asked Jul 27 · Concept · Junior

  103. What is a firewall?

    Asked once · last asked Aug 6 · Concept · Junior

  104. When using RDP, which host or system does the user connect to?

    Asked once · last asked Aug 20 · Concept · Junior

  105. Can a user access the internet from a remote desktop session?

    Asked once · last asked Aug 20 · Scenario · Junior

  106. What authentication methods are used by different network protocols?

    Asked once · last asked Aug 24 · Concept · Junior

  107. In a firewall configuration, when would you create an object versus add a static route?

    Asked once · last asked Sep 17 · Concept · Mid-level

  108. What do you usually do when working with firewalls?

    Asked once · last asked Sep 18 · Tooling · Mid-level

  109. Can you explain DNS and SSL?

    Asked once · last asked Sep 19 · Concept · Junior

  110. How are firewall settings typically configured in a corporate environment?

    Asked once · last asked Sep 30 · Scenario · Mid-level

  111. What do you mean by a VPN network?

    Asked once · last asked Jan 8 · Concept · Junior

  112. How does a VPN provide network connectivity?

    Asked once · last asked Jan 8 · Concept · Junior

  113. What types of cryptography are used during a TLS handshake?

    Asked once · last asked Jan 23 · Concept · Junior

More Computer Networks interview questions

How this list is made

Every question here was asked by a real interviewer in a real job interview that a candidate ran MeetAssist in. After the call, the interviewer's questions are pulled from the transcript. Practice sessions, tests, exams and anything that was not a job interview are dropped.

Questions are rewritten so they make sense on their own: names of people, employers and clients are removed, and speech-to-text mistakes are fixed. Small talk, logistics and questions about one candidate's own résumé are left out. Rephrasings of the same question are merged, and the count is the number of different interviews it came up in.

The interviews come from candidates who use MeetAssist, so they lean towards software, data and AI roles: the shares describe these interviews, not every Computer Networks interview. Answers to the most asked questions are written and checked by an editor; a "common mistake" is shown only when reviews of real answers in these interviews show it, with the count.

337 interviews, 208 candidates, Nov 2025 to Oct 2026. Updated every month with new interviews.