45+ Top Cisco Interview Questions and Answers to Excel in 2025

Cisco powers networking, cybersecurity, and enterprise solutions, enabling high-speed data, secure cloud environments, and AI-powered automation. With hybrid cloud adoption surging and real-time applications reshaping industries, professionals skilled in SD-WAN, network security, and automation are increasingly sought after.

The Cisco interview questions and answers focus on core networking concepts, cloud integrations, and security frameworks. Alongside technical assessments, Cisco HR interview questions evaluate problem-solving and adaptability. 

This guide equips you with the knowledge to navigate each stage confidently and secure a role at Cisco. 

Essential Cisco Interview Questions for Freshers: Key Insights & Tips

A strong grasp of networking fundamentals is crucial for freshers preparing for a Cisco interview. You can expect questions on OSI and TCP/IP models, subnetting, routing protocols, and network security concepts. Hands-on knowledge of Cisco devices and basic troubleshooting is also essential. 

To build confidence, focus on practical lab exercises, review Cisco’s official documentation, and practice problem-solving scenarios.

Let’s explore 15 Cisco interview questions and answers for freshers.

1. What Is a Firewall, and How Does It Enhance Network Security?

A firewall is a security device or software that monitors and controls incoming and outgoing network traffic based on predefined rules. It acts as a barrier between trusted and untrusted networks, preventing unauthorized access, malware, and cyber threats.

To secure enterprise networks, Cisco firewalls use stateful inspection, deep packet filtering, and intrusion prevention systems (IPS). While stateful firewalls track active connections, DPI (a feature of next-generation firewalls) analyzes packet contents to detect and block advanced threats. 

These firewalls enforce security policies, block suspicious traffic, and protect against attacks like DDoS, man-in-the-middle (MITM) attacks, and zero-day exploits. Here are key ways firewalls enhance network security:

• Traffic Filtering: Blocks or allows traffic based on source, destination, and protocol.
• Intrusion Detection & Prevention: Identifies and stops malicious activities in real time.
• VPN Support: Secures remote access with encrypted tunnels.
• Application-Layer Security: Analyzes data packets for threats beyond basic IP filtering.

2. Define a Network Link and Its Significance in Data Communication

A network link is a physical or logical connection between two or more devices, enabling data transmission. It can be wired (Ethernet, fiber optic) or wireless (Wi-Fi, satellite).

Network links ensure efficient communication, data integrity, and seamless connectivity between nodes. Their reliability directly impacts network performance, affecting latency, throughput, and packet loss.

Key aspects that define the efficiency of a network link:

• Bandwidth: Determines the amount of data transmitted per second.
• Latency: Measures the delay between data transmission and reception.
• Duplex Mode: Full-duplex links allow simultaneous transmission and reception, reducing bottlenecks.
• Error Handling: Implements error correction to maintain data integrity.

Also Read: Computer Networking Basics: Network Types, Technologies, Topologies, Pros and Cons

3. What Is the Default TCP Session Timeout in Cisco Devices?

The default TCP session timeout in Cisco devices varies based on the device type, model, and configuration settings. For instance, Cisco routers typically have a TCP timeout of 24 hours, while Cisco ASA firewalls default to one hour (3,600 seconds) for idle connections. This setting determines how long an inactive session remains open before termination to free up system resources.

Proper session timeout adjustments help optimize network performance, security, and resource utilization. Longer timeouts benefit persistent applications like VoIP and real-time messaging, whereas shorter timeouts reduce the risk of session hijacking.

For better performance, Cisco Adaptive Security Appliance (ASA) allows timeout customization using:

ASA(config)# timeout conn 1800

This sets the timeout to 30 minutes instead of the default. Adjusting timeouts based on network needs prevents unnecessary disconnections while securing critical sessions.

4. Explain the Concept of a Diskless Workstation and Its Advantages

A diskless workstation is a computer that operates without a local hard drive, retrieving its operating system and data from a central server. It relies on network boot protocols like PXE (Preboot Execution Environment) and NFS (Network File System) for system files and storage access.

These workstations enhance centralized management, cost efficiency, and security, making them ideal for schools, call centers, and research labs. However, while eliminating local data storage reduces certain malware risks, threats can still spread through the network or shared resources.

Here are some advantages of diskless workstations: 

Diskless environments are common in cloud computing and VDI (Virtual Desktop Infrastructure), improving scalability and security in corporate networks.

5. What Is Routing, and Why Is It Essential in Networking?

Routing is the process of selecting the best path for data packets to travel across a network. It ensures efficient communication between devices in different networks.

Without routing, data cannot move beyond its local subnet, limiting connectivity. Routers analyze packet headers, determine optimal paths, and forward data accordingly. Cisco routers use protocols like OSPF, EIGRP, and BGP to make dynamic routing decisions.

Key reasons routing is essential in networking:

• Efficient Data Transmission: Ensures packets reach their destination via the best path.
• Network Scalability: Enables communication across large networks, including the internet.
• Redundancy & Load Balancing: Reroutes traffic in case of link failures, preventing downtime.
• Security & Traffic Control: Implements access control lists (ACLs) to filter traffic.

6. List and Describe the Different Types of Memory Used in a Cisco Router

Cisco routers use multiple memory types, each serving a specific function for system operation, configuration, and packet handling. Understanding these memory types is crucial for troubleshooting and performance optimization.

Below is a breakdown of the memory types in a Cisco router:

Efficient memory management ensures seamless network operations, especially in high-traffic environments.

Also Read: Types of Memory in Computers and Their Uses with Examples

7. How Do a Hub, Switch, and Router Differ in Terms of Functionality?

Hubs, switches, and routers manage network traffic but operate at different OSI layers and serve distinct purposes. Understanding these differences helps in designing optimized network architectures.

The table below lists out the functional differences between each:

While hubs are rarely used today due to inefficiency, switches and routers remain essential for LAN and WAN connectivity.

Also Read: Difference between Hub and Switch

8. What Is a VLAN, and How Does It Improve Network Efficiency?

A VLAN (Virtual Local Area Network) is a logically segmented network within a physical switch. It separates devices into different broadcast domains without requiring additional hardware.

VLANs enhance network performance, security, and manageability. They reduce unnecessary broadcast traffic, preventing congestion in large networks.

Key benefits of VLANs:

• Traffic Segmentation: Separates departments (e.g., HR and Finance) for better security.
• Improved Performance: Reduces broadcast storms and network load.
• Enhanced Security: Limits access between VLANs, reducing attack surfaces.
• Simplified Management: Easier to apply policies and troubleshoot issues.

By isolating traffic logically, VLANs optimize enterprise networks, supporting better resource utilization and security compliance.

9. How Does a Subnet Mask Work, and Why Is It Important?

A subnet mask defines which part of an IP address represents the network and which part identifies the host. It allows efficient IP address allocation and routing.

Without subnetting, networks become congested, leading to inefficient data transmission. Subnet masks divide networks into smaller segments, reducing broadcast traffic and improving security.

Key reasons subnet masks are essential:

• Efficient Addressing: Helps allocate IP addresses properly within an organization.
• Traffic Management: Reduces congestion by limiting broadcast domains.
• Security & Isolation: Segments networks for enhanced access control.
• Optimized Routing: Enables routers to make precise forwarding decisions.

For example, in 192.168.1.0/24, the subnet mask 255.255.255.0 indicates that the first three octets define the network, while the last octet specifies the host.

10. What Is a MAC Address, and How Does It Impact Network Communication?

A MAC (Media Access Control) address is a unique 48-bit identifier assigned to a network interface card (NIC). It operates at the Data Link Layer (Layer 2) of the OSI model.

Unlike IP addresses, MAC addresses remain fixed and are used for local network communication. When a device sends data, it relies on the MAC address to reach the intended recipient within a LAN.

Key roles of MAC addresses in network communication:

• Device Identification: Ensures unique hardware recognition in a network.
• Data Forwarding: Switches use MAC addresses to send packets efficiently.
• Security: MAC filtering helps prevent unauthorized device access.
• Address Resolution: Used by ARP to map IP addresses to MAC addresses.

For example, a MAC address like 00:1A:2B:3C:4D:5E allows Ethernet frames to be delivered accurately, preventing data loss and misrouting.

11. What Are the Key Differences Between Static and Dynamic Routing?

Routing determines how packets move between networks. Static and dynamic routing are two fundamental approaches, each with distinct advantages and use cases. Static routes, with an administrative distance of 1, take precedence over many dynamic routes, making them suitable for default routing and simple connections. 

However, dynamic routing is more scalable and adjusts automatically to network changes. Below is a comparison of static and dynamic routing:

For enterprises, static routes are ideal for stable, predictable paths, such as branch office connections and default routes. In contrast, dynamic routing ensures high availability, automated failover, and better adaptability in large-scale networks.

12. How Does the Address Resolution Protocol (ARP) Function in a Network?

ARP (Address Resolution Protocol) maps an IP address to a MAC address within a local network. This process is essential for device-to-device communication in a LAN.

When a device sends data, it needs the recipient’s MAC address. If unknown, it broadcasts an ARP request. The target device responds with its MAC address, enabling direct data transmission.

Key ARP functions in networking:

• IP-to-MAC Mapping: Ensures packets reach the correct physical device.
• Efficient Communication: Prevents delays in local network data exchange.
• Caching for Speed: Stores resolved MAC addresses to reduce future ARP requests.
• Security Considerations: Susceptible to ARP spoofing, requiring mitigation techniques like Dynamic ARP Inspection (DAI).

For example, running the arp -a command on a system displays cached ARP entries, showing mapped MAC addresses for known IPs, improving efficiency in network communication.

13. What Role Does a Default Gateway Play in Network Communication?

A default gateway is the IP address of a router that forwards packets from a local network to external networks when no specific route is available. It acts as an intermediary between a local subnet and other networks, including the internet.

Without a default gateway, devices can only communicate within their own subnet. The router uses its routing table to determine the best path for outgoing traffic.

Key functions of a default gateway:

• Inter-network Communication: Enables devices to access external networks.
• Packet Forwarding: Routes traffic when no direct path is found.
• Traffic Management: Directs traffic efficiently, reducing congestion.
• Security Filtering: Can enforce policies via ACLs and firewalls.

For example, if a device has the IP 192.168.1.10/24, and the default gateway is 192.168.1.1, all non-local traffic is sent to 192.168.1.1 for further routing.

Also Read: A Guide for Understanding the Networking Commands

14. Compare IPv4 and IPv6 in Terms of Structure, Security, and Scalability

IPv4 and IPv6 are the two primary internet protocols, but IPv6 was developed to address the limitations of IPv4. The table below highlights key differences.

IPv6 enhances security, efficiency, and scalability, making it essential for modern networks, cloud applications, and IoT deployments.

15. Explain Network Address Translation (NAT) and Its Practical Applications

Network Address Translation (NAT) allows multiple devices in a private network to share a single public IP address, conserving IPv4 addresses and improving security.

NAT modifies IP address information in packet headers, enabling devices with private IPs (192.168.x.x, 10.x.x.x, 172.16.x.x) to communicate over the internet.

Practical applications of NAT:

• IPv4 Address Conservation: Reduces the need for unique public IPs.
• Security Enhancement: Hides internal IPs, making networks less vulnerable.
• Enterprise & Home Networks: Allows multiple devices to access the internet using one public IP.
• Load Balancing (NAT Load Balancer): Distributes traffic efficiently across multiple servers.

For example, a home router uses PAT (Port Address Translation) to allow multiple devices to access the internet via one public IP while maintaining separate internal connections.

Building a strong foundation is essential, but excelling in a Cisco interview requires advanced knowledge. Let’s explore expert-level questions and strategies for professionals.

Cisco Interview Questions and Expert-Level Answers for Professionals

To excel in Cisco interviews, you must master advanced concepts like VLANs, ACLs, and automation using Cisco’s CLI and Python scripting. Strong expertise in packet flow analysis, security policies, and IP routing strategies enhances your problem-solving capabilities. 

Let’s explore 15 expert level Cisco interview questions and answers. 

16. How Does the Dynamic Host Configuration Protocol (DHCP) Assign IP Addresses?

DHCP (Dynamic Host Configuration Protocol) automatically assigns IP addresses to devices, eliminating manual configuration and reducing address conflicts. It operates using a client-server model.

When a device joins a network, it sends a DHCPDISCOVER request. The DHCP server responds with an DHCPOFFER, providing an available IP address. The client then sends a DHCPREQUEST to confirm, and the server grants the lease with a DHCPACK.

Key DHCP functions:

• IP Address Assignment: Allocates unique addresses dynamically.
• Lease Expiration: Ensures efficient reuse of IPs.
• Configuration Delivery: Assigns subnet masks, gateways, and DNS settings.
• Scalability: Supports large enterprise networks efficiently.

For example, corporate networks use DHCP relay agents to distribute addresses across multiple VLANs, reducing administrative overhead.

Also Read: Best 21+ CMD Network Commands for IT Professionals in 2025

17. What Is the Purpose of Port Numbers in Networking, and How Are They Assigned?

Port numbers identify specific applications or services running on a device, enabling organized network communication. They ensure data reaches the correct process.

Each protocol has an assigned port range, standardized by IANA (Internet Assigned Numbers Authority). There are three main categories:

For example, a web server listens on port 80 (HTTP), ensuring requests reach the right service without interference.

18. How Does the Internet Control Message Protocol (ICMP) Contribute to Network Troubleshooting?

ICMP (Internet Control Message Protocol) helps diagnose network issues by providing error messages and operational information. It works alongside IP but doesn’t carry application data.

It is primarily used for network diagnostics, reachability tests, and error reporting. Below are key ICMP functions:

• Ping (Echo Request/Reply): Tests connectivity and measures latency.
• Traceroute (Time Exceeded): Identifies network paths and delays.
• Destination Unreachable: Indicates routing or firewall issues.
• Packet Fragmentation Alerts: Prevents data transmission failures.

For example, if a device fails to respond to a ping request, it could indicate network congestion, incorrect routing, or a security filter blocking ICMP traffic.

19. Differentiate Between Layer 2 and Layer 3 Switches and Their Respective Use Cases

Layer 2 and Layer 3 switches differ in how they handle traffic. While Layer 2 switches work with MAC addresses, Layer 3 switches use IP addresses for routing.

The key differences are:

For example, Layer 3 switches replace traditional routers in large networks, reducing bottlenecks and improving efficiency.

20. What Is the Difference Between an Access Point and a Router in a Wireless Network?

An access point (AP) extends a wired network by providing wireless connectivity, while a router directs traffic between networks and assigns IP addresses.

Here’s how they differ:

For example, enterprise networks use multiple APs managed by a wireless controller, ensuring seamless connectivity across large areas.

21. How Is a TCP Connection Established, and What Is the Significance of the Three-Way Handshake?

A TCP connection is established using a three-way handshake, ensuring reliable communication between two devices before data transmission begins.

The handshake process consists of three steps:

1. SYN (Synchronize): The client sends a SYN packet to initiate a connection.
2. SYN-ACK (Synchronize-Acknowledge): The server responds with a SYN-ACK packet, acknowledging the request.
3. ACK (Acknowledge): The client replies with an ACK, establishing the connection.

This process prevents data loss, ensures synchronization, and mitigates spoofing attacks. If interrupted, TCP retransmits lost packets for reliable communication.

For example, HTTPS, FTP, and SSH rely on TCP’s handshake for secure and ordered data delivery.

22. What Is Cut-Through LAN Switching, and How Does It Compare to Store-and-Forward Switching?

Cut-through switching forwards frames as soon as the destination MAC address is read, reducing latency but increasing error propagation risk.

Store-and-forward switching examines the entire frame before forwarding, ensuring data integrity but introducing slight delays.

The table below shows the key differences between cut-through LAN switching and store-and-forward switching:

For example, cut-through switching benefits real-time applications like VoIP, while store-and-forward switching is used in data centers where error checking is crucial.

23. What Is Recovery Testing, and How Does It Apply to Network Systems?

Recovery testing evaluates how a network system responds to failures and restores operations after disruption. It ensures resilience and high availability in enterprise environments.

Key aspects of recovery testing:

• Failure Detection: Simulates hardware failures, software crashes, or link outages.
• Redundancy Checks: Validates backup routers, switches, and failover mechanisms.
• Disaster Recovery Scenarios: Tests data restoration from backups.
• Performance Validation: Measures recovery time and system stability post-failure.

For example, BGP routers use failover mechanisms to reroute traffic in case of link failures, ensuring continuous connectivity.

24. Explain Context Switching in Networking and What Triggers It

Context switching occurs when a device switches between multiple processes or tasks, typically in networking hardware, routers, and firewalls.

Triggers for context switching:

• Interrupt Handling: High-priority network events require immediate processing.
• Multitasking: Routers process multiple routing protocols and firewall rules simultaneously.
• Load Balancing: Network devices switch between tasks to optimize performance.
• Packet Processing: Firewalls inspect packets, applying security policies dynamically.

For example, high-performance routers use hardware acceleration to minimize context-switching delays, ensuring efficient packet forwarding.

25. Provide an Overview of the Seven OSI Model Layers and Their Functions

The OSI (Open Systems Interconnection) model standardizes network communication across seven layers, defining how data is transmitted and processed.

The table below lists out the types of OSI model layers and its functions with examples:

For example, Layer 3 routing protocols like OSPF determine the best path for data across networks, ensuring efficient communication.

26. What Is the Spanning Tree Protocol (STP), and How Does It Prevent Network Loops?

Spanning Tree Protocol (STP) prevents network loops in redundant Layer 2 Ethernet networks by blocking unnecessary paths while maintaining connectivity. Without STP, broadcast storms and MAC table corruption occur.

STP operates by electing a Root Bridge, then calculating the best path to it, disabling redundant links. Key STP functions:

• Bridge ID & Root Election: The switch with the lowest Bridge ID becomes the Root Bridge.
• Path Selection: STP assigns ports as Root, Designated, or Blocking based on cost.
• Loop Prevention: Blocked ports prevent loops while allowing failover if active links fail.

For example, Rapid Spanning Tree Protocol (RSTP) enhances STP, reducing convergence time and improving network resilience.

27. How Would You Approach Troubleshooting a Major Network Outage in an Enterprise Environment?

A structured approach ensures quick resolution and minimal downtime. Start with high-impact areas, then systematically isolate and resolve issues.

Key troubleshooting steps:

1. Identify Impact: Assess affected users, devices, and services.
2. Check Physical Layer: Inspect cables, power, and link status.
3. Verify Routing & Switching: Ensure VLANs, routes, and STP are functioning.
4. Analyze Logs & Alerts: Use syslogs and SNMP traps for issue identification.
5. Test Connectivity: Use ping, traceroute, and nslookup to verify reachability.
6. Check Security Policies: Ensure firewalls and ACLs are not blocking traffic.
7. Escalate if Needed: Involve vendors or ISPs if external factors are suspected.

For example, BGP flaps or misconfigured ACLs can cause widespread outages; timely troubleshooting minimizes business impact.

28. Compare Stateful and Stateless Firewalls in Terms of Security and Efficiency

Firewalls filter traffic based on predefined rules. Stateful firewalls track active connections, while stateless firewalls analyze individual packets without context.

Here’s a comparison between stateful and stateless firewalls on the basis of its features:

For example, Cisco ASA firewalls use stateful inspection, providing granular control over TCP, UDP, and ICMP sessions.

29. How Does Border Gateway Protocol (BGP) Prevent Routing Loops, and Why Is It Essential for ISPs?

BGP (Border Gateway Protocol) prevents routing loops using path control mechanisms and AS-path filtering, ensuring efficient and stable internet routing. It plays a critical role in inter-domain routing, allowing ISPs to manage large-scale networks.

BGP prevents loops through:

• AS-Path Attribute: Routers reject routes containing their own Autonomous System (AS) number, preventing loops in inter-domain BGP (eBGP).
• Route Filtering: ISPs apply policies to block invalid or suspicious routes based on predefined filtering rules.
• Loop Prevention in iBGP: iBGP does not use the AS-path to detect loops, so full mesh connectivity is required. To scale large networks, Route Reflectors (RRs) and BGP Confederations reduce the need for full-mesh connections.

BGP is crucial for ISPs and large enterprises, enabling multi-homing, traffic engineering, and policy-based routing to optimize internet connectivity.

While BGP alone does not prevent hijacking, mechanisms like Route Origin Validation (ROV) and Resource Public Key Infrastructure (RPKI) secure BGP route announcements against hijack attempts. Misconfigured AS-path manipulation can lead to BGP hijacking incidents, disrupting global traffic.

30. Explain the Purpose of Hot Standby Router Protocol (HSRP) and How It Ensures Network Redundancy

HSRP (Hot Standby Router Protocol) is a Cisco proprietary protocol that provides router redundancy by allowing multiple routers to act as a single virtual gateway for end devices. It ensures failover protection, preventing downtime if the active router fails.

HSRP Functionality:

• Virtual IP & MAC: Devices use a virtual gateway IP, ensuring seamless failover without reconfiguring clients.
• Primary & Standby Roles: One router is designated as Active, while another is on Standby, ready to take over.
• Failover Detection: If the Active router fails, the Standby router assumes the role immediately, ensuring network continuity.

How HSRP Differs From Other Redundancy Protocols:

• HSRP (Cisco proprietary): Provides redundancy but does not support load balancing between multiple routers.
• VRRP (Virtual Router Redundancy Protocol - Open Standard): Similar to HSRP but can be used across multi-vendor networks.
• GLBP (Gateway Load Balancing Protocol - Cisco proprietary): Unlike HSRP and VRRP, GLBP distributes traffic across multiple routers, providing both redundancy and load balancing.

Enterprises deploy HSRP in data centers to ensure uninterrupted access to mission-critical applications and cloud services, minimizing downtime.

We have covered most of the descriptive questions. Now,, test your Cisco expertise with MCQs that challenge your understanding of key concepts.

Cisco Multiple-Choice Questions (MCQs) with Detailed Explanations

Assessing your understanding of networking protocols, security frameworks, and system architecture through multiple-choice questions is a great way to reinforce key concepts. This section presents carefully crafted Cisco MCQs, covering topics such as routing protocols, firewall security, VLAN configurations, and network troubleshooting. 

31. Which of the following is an IP routing protocol?

A) RIP

B) ARP

C) ARUP

D) ICMP

A: Correct Answer: A) RIP

Explanation:
Routing Information Protocol (RIP) is a distance-vector IP routing protocol used to determine the best path for data packets. It operates at Layer 3 (Network Layer) and uses hop count as its metric, with a limit of 15 hops to prevent routing loops.

The incorrect options serve different purposes:

• ARP (Address Resolution Protocol) resolves IP addresses to MAC addresses.
• ICMP (Internet Control Message Protocol) handles network diagnostics and error reporting.
• ARUP is not a valid networking protocol.

Modern networks often replace RIP with OSPF or BGP, which offer better scalability and faster convergence.

32. Which Statement About IGRP Is Incorrect?

A) Supports multiple unequal paths

B) Administrative distance is 100

C) Uses hop count as a metric

D) Requires an autonomous system number

A: Correct Answer: C) Uses hop count as a metric

Explanation:
Interior Gateway Routing Protocol (IGRP), developed by Cisco, does not rely solely on hop count as a metric. Instead, it calculates the best route using bandwidth, delay, reliability, and load.

The other statements are correct:

• Supports multiple unequal paths: Uses variance to allow unequal-cost load balancing.
• Administrative distance is 100: Defines its priority in routing tables.
• Requires an autonomous system number: Identifies routing domains.

Unlike RIP, which uses only hop count, IGRP provides better path selection in large networks, making it more efficient for enterprise routing.

33. Which OSI Layer Is Responsible for Encryption, Formatting, and Code Conversion?

A) Presentation

B) Physical

C) Session

D) Application

A: Correct Answer: A) Presentation

Explanation:
The Presentation Layer (Layer 6) of the OSI model is responsible for data encryption, formatting, compression, and code conversion to ensure compatibility between different systems.

The incorrect options serve different functions:

• Physical Layer (Layer 1): Handles raw data transmission through cables or wireless signals.
• Session Layer (Layer 5): Manages session establishment, maintenance, and termination.
• Application Layer (Layer 7): Provides end-user services like email, web browsing, and file transfers.

For example, SSL/TLS encryption occurs at the Presentation Layer, ensuring secure data transmission between clients and servers in applications like HTTPS and VPNs.

34. Which of the Following Best Describes Half-Duplex Communication?

A) Doubles available bandwidth

B) Works only in point-to-point configurations

C) Allows data transmission and reception, but not simultaneously

D) Supports simultaneous data transmission and reception

A: Correct Answer: C) Allows data transmission and reception, but not simultaneously

Explanation:
Half-duplex communication allows devices to transmit and receive data but not at the same time. It operates similarly to a two-way radio, where only one party speaks at a time.

The incorrect options:

• A) Bandwidth remains the same, as only one direction is active at a time.
• B) Works in both point-to-point and shared media networks.
• D) Full-duplex, not half-duplex, supports simultaneous transmission.

For example, legacy Ethernet networks (e.g., 10BASE-T using hubs) operate in half-duplex mode, causing potential collisions.

35. Which Protocol Is Used to Dynamically Assign IP Addresses?

A) DNS

B) DHCP

C) ARP

D) SMTP

A: Correct Answer: B) DHCP

Explanation:
Dynamic Host Configuration Protocol (DHCP) automatically assigns IP addresses, subnet masks, gateways, and DNS settings to network devices, reducing manual configuration and preventing IP conflicts.

The incorrect options serve different purposes:

• DNS (Domain Name System): Resolves domain names to IP addresses.
• ARP (Address Resolution Protocol): Maps IP addresses to MAC addresses.
• SMTP (Simple Mail Transfer Protocol): Handles email transmission.

For example, when a device connects to a network, it sends a DHCPDISCOVER request, and the DHCP server assigns an IP from its pool, ensuring seamless connectivity.

36. What Is the Default Administrative Distance of OSPF?

A) 110

B) 90

C) 120

D) 100

A: Correct Answer: A) 110

Explanation:
Open Shortest Path First (OSPF) has a default administrative distance (AD) of 110, meaning it is preferred over RIP (120) but less preferred than EIGRP (90).

The incorrect options:

• B) 90: Used by EIGRP for internal routes.
• C) 120: Used by RIP.
• D) 100: Used by IGRP (legacy Cisco protocol).

For example, in a network running OSPF and RIP, the router will prefer OSPF routes due to their lower AD value, ensuring more efficient path selection.

37. Which OSI Layer Handles Error Detection and Correction?

A) Transport

B) Network

C) Data Link

D) Application

A: Correct Answer: C) Data Link

Explanation:
The Data Link Layer (Layer 2) is responsible for error detection and correction using techniques like cyclic redundancy check (CRC) and frame check sequence (FCS).

The incorrect options serve different purposes:

• Transport Layer (Layer 4): Handles end-to-end communication and error recovery (e.g., TCP retransmissions).
• Network Layer (Layer 3): Manages routing but does not correct errors.
• Application Layer (Layer 7): Provides services to users but does not handle transmission errors.

For example, Ethernet frames use FCS to detect errors before forwarding data, ensuring reliable LAN communication.

38. What Is the Maximum Recommended Cable Length for CAT6 to Maintain Optimal Performance?

A) 100 meters

B) 50 meters

C) 150 meters

D) 200 meters

A: Correct Answer: A) 100 meters

Explanation:
The maximum recommended length for CAT6 Ethernet cables is 100 meters (328 feet), including 90 meters for permanent link + 10 meters for patch cables. Beyond this, signal degradation and crosstalk increase, reducing performance.

The incorrect options:

• B) 50 meters: Shorter than required for standard applications.
• C) 150 meters / D) 200 meters: Exceed the signal integrity limits of twisted-pair cabling.

For 10Gbps transmission, CAT6 is limited to 55 meters, while CAT6A supports 100 meters for 10GbE networks.

39. Which Command Displays the Running Configuration of a Cisco Router?

A) show ip route

B) show run

C) show version

D) config t

A: Correct Answer: B) show run

Explanation:
The show run command displays the current running configuration stored in RAM on a Cisco router or switch. It includes active interfaces, routing protocols, and security settings.

The incorrect options:

• A) show ip route: Displays the router's routing table, not configuration settings.
• C) show version: Shows system details like IOS version, uptime, and hardware info.
• D) config t: Enters global configuration mode but does not display settings.

For example, to verify ACLs, VLANs, or NAT settings, network engineers use show run to troubleshoot and confirm live configurations.

40. What Is the Function of the "Ping" Command in Network Troubleshooting?

A) Measures network bandwidth

B) Tests connectivity between devices

C) Configures router interface

D) Detects potential cyber threats

A: Correct Answer: B) Tests connectivity between devices

Explanation:
The ping command tests network connectivity between two devices by sending ICMP Echo Request packets and waiting for a reply. It helps diagnose latency, packet loss, and reachability issues.

The incorrect options:

• A) Measures network bandwidth: ping measures response time, not bandwidth.
• C) Configures router interfaces: Configuration requires interface commands in privileged mode.
• D) Detects potential cyber threats: ping does not analyze threats; it only checks connectivity.

For example, running ping 8.8.8.8 verifies if a device can reach Google’s public DNS, confirming internet access.

Technical skills are essential, but securing a role at Cisco also requires strong communication, problem-solving, and cultural fit. Let’s explore key HR interview questions and strategies.

Cisco HR Interview Questions for Both Entry-Level & Experienced Candidates

Cisco’s HR interviews assess behavioral, situational, and leadership skills to ensure candidates align with the company’s culture and values. Expect questions about teamwork, conflict resolution, adaptability, and problem-solving. Your responses should follow structured frameworks like the STAR (Situation, Task, Action, Result) method to demonstrate clear, results-driven thinking. 

41. Why Do You Want to Work at Cisco, and What Interests You About This Role?

Best Approach:

Employers look for candidates who align with Cisco’s mission, technology, and culture. Your answer should reflect genuine enthusiasm and a clear understanding of the role.

Example Answer:

"I am drawn to Cisco’s commitment to innovation in networking, cybersecurity, and automation. The company’s impact on global connectivity and enterprise solutions excites me. 

This role aligns with my expertise in network engineering and cloud technologies, allowing me to contribute to innovative solutions while growing in a collaborative environment."

42. What Are Your Biggest Strengths and Weaknesses, and How Do They Impact Your Work?

Best Approach:

Highlight a strength that directly benefits the role and a weakness with a solution that shows self-awareness and improvement.

Example Answer:

"One of my strengths is troubleshooting complex network issues. I excel at analyzing packet flows and identifying root causes efficiently. However, my weakness is overanalyzing problems, which sometimes slows decision-making. To improve, I set time limits for analysis and prioritize solutions based on business impact."

43. Describe the Most Challenging Networking Problem You've Faced and How You Resolved It.

Best Approach:

Use the STAR method (Situation, Task, Action, Result) to provide a structured and impactful response.

Example Answer:

"While working on a multi-site VPN deployment, I encountered high latency and packet drops affecting remote offices. I analyzed traffic patterns, identified MTU mismatches, and adjusted configurations to optimize packet transmission.

By implementing QoS policies and proper fragmentation, I reduced latency by 40%, improving network stability and user experience."

44. What Qualities Make You a Strong Candidate for a Network Engineering Role?

Best Approach:

Cisco values technical expertise, problem-solving skills, and adaptability. Showcase your unique combination of these traits.

Example Answer:

"My strong foundation in routing protocols, automation (Python for network scripting), and cybersecurity makes me well-suited for this role. I thrive in fast-paced environments, adapt to emerging technologies, and proactively seek efficiency improvements.

Additionally, my experience in cross-functional collaboration enables me to work effectively across IT and business teams."

45. How Do You Manage and Prioritize Multiple Tasks in a High-Pressure Environment?

Best Approach:

Demonstrate time management, prioritization, and stress-handling strategies. Cisco values professionals who stay composed under pressure.

Example Answer:

"I prioritize tasks based on impact and urgency, using tools like Kanban boards and automation to streamline workflows. When managing multiple high-priority incidents, I apply the 80/20 rule, addressing the most critical 20% of issues that impact 80% of network performance. 

Effective communication with stakeholders ensures expectations are aligned, and delegation maximizes efficiency."

46. Why Are You Looking for a Change From Your Current Job?

Best Approach:

Stay professional and positive. Focus on career growth, new challenges, or alignment with Cisco’s vision, rather than negative experiences.

Example Answer:

"I’ve gained valuable experience in my current role, particularly in network automation and security. However, I’m looking for greater exposure to large-scale networking environments and an opportunity to work on cutting-edge technologies like SD-WAN and cloud networking. Cisco’s commitment to innovation makes it an ideal place for my next career step."

47. Where Do You See Yourself Professionally in the Next Ten Years?

Best Approach:

Show ambition and long-term commitment while aligning your goals with Cisco’s growth opportunities.

Example Answer:

"In the next ten years, I aim to be a senior network architect leading innovative projects in cloud networking and cybersecurity. I plan to earn advanced certifications like CCIE and CISSP, contribute to network automation strategies, and mentor junior engineers. 

Cisco’s leadership in AI-driven networking and enterprise security makes it the ideal place to build my long-term career."

48. How Do You Handle Tight Deadlines and High-Stress Situations?

Best Approach:

Demonstrate structured problem-solving, prioritization, and composure in high-pressure situations.

Example Answer:

"I break complex tasks into manageable priorities, focusing on critical-path items first. In high-pressure incidents, I apply troubleshooting frameworks (like OSI model analysis) to diagnose and resolve issues efficiently. 

Clear communication with stakeholders ensures expectations are aligned. In my previous role, I resolved a network outage under tight SLAs by leading a rapid-response team, restoring services within 30 minutes."

49. Can You Share an Experience Where You Had to Mediate a Conflict Within a Team?

Best Approach:

Highlight conflict resolution skills, collaboration, and diplomacy using the STAR method.

Example Answer:

"During a data center migration, a disagreement arose between network and security teams over firewall rule changes. I facilitated a technical discussion, clarifying the security impact while ensuring network efficiency. 

By proposing a compromise (temporary access controls + post-migration audits), I resolved the conflict, ensuring project success and team alignment."

50. What Steps Do You Take to Stay Updated on the Latest Networking Technologies and Industry Trends?

Best Approach:

Show continuous learning, professional development, and adaptability.

Example Answer:

"I stay updated by following Cisco Live events, RFCs, and networking forums. I actively pursue certifications like CCNP Enterprise, experiment with lab simulations (GNS3, EVE-NG), and engage in open-source network automation projects. 

Additionally, I participate in Cisco DevNet and attend industry webinars to stay ahead of evolving trends in SDN, AI-driven networking, and cybersecurity."

Knowing the answers isn't enough; presenting them effectively is what sets you apart. Let’s explore proven strategies to ace your Cisco interview.

Proven Strategies to Succeed in Cisco Job Interviews

Securing a job at Cisco requires technical expertise, problem-solving skills, and strong communication. A structured preparation plan ensures confidence in every interview round.

Key Strategies for Success:

• Technical Revision: Review networking fundamentals, Cisco architectures, and automation concepts using Cisco’s official documentation and hands-on labs.
• Mock Interviews: Practice technical and behavioral questions with peers or mentors to improve response clarity.
• Scenario-Based Problem Solving: Be ready to troubleshoot real-world networking issues, applying OSI model analysis and protocol debugging.
• Clear and Concise Communication: Use the STAR method for behavioral responses and explain technical concepts in simple, structured terms.
• Understanding Cisco’s Culture: Research Cisco’s values, leadership principles, and innovation areas to align your answers with their mission.
• Time Management in Assessments: During technical tests, prioritize efficient solutions and explain your thought process clearly.

With the right preparation, structured practice, and technical depth, you can approach your Cisco interview with confidence and secure your dream role.

How Can upGrad Support Your Cisco Interview Preparation Journey?

Cracking a Cisco interview requires strong networking skills and hands-on experience. upGrad provides expert-led courses, real-world labs, and training in security, automation, and cloud networking.

You’ll gain practical expertise in Cisco architectures, SDN, DevOps integration, and network troubleshooting, ensuring you’re fully prepared for any interview scenario.

Gaining certifications and hands-on experience before your Cisco interview boosts your expertise. These upGrad programs help you develop in-demand skills and stand out in hiring.

• AI-Powered Full Stack Development Course by IIITB
• Professional Certificate Program in Cloud Computing and DevOps
• Cloud Computing and DevOps Program by IIITB - (Executive)

Here are some free courses you can complete in under a day to strengthen your foundational knowledge before your Cisco interview:

• Fundamentals of Cloud Computing
• JavaScript Basics from Scratch

Book your free personalized career counseling session today and take the first step toward transforming your future. For more details, visit the nearest upGrad offline center.