Network Automation is now an essential skill, as modern networks are difficult to manage with manual CLI commands. Today, companies require professionals who are proficient in using Python, Ansible, APIs, JSON, YAML as well as automation software to set up devices, eliminate mistakes, measure performance, and solve problems faster. This transition from traditional network to automated workflows is the primary reason for the rising need for network automation experts.
The network automation interview questions and answers that we’ve discussed in the blog are especially for students, CCNA/CCNP learners, Network engineers, DevOps Engineers, as well as all who are preparing for network automation interviews and want to transition away from the manually based CLI work to automated workflows.
Network Automation Interview Questions and Answers
Below, we have discussed the most asked network automation interview questions and answers along with examples for better understanding.
Q1. What is network automation?
Network automation means using software to perform network tasks automatically and repeatedly. It replaces repetitive manual CLI work and reduces human mistakes. Teams automate configuration changes, backups, monitoring checks, and compliance validation across devices.
Q2. Why is network automation important?
Network automation is important because networks scale faster than manual operations can handle. It improves speed, consistency, and reliability during routine changes and troubleshooting. Automation also supports stronger security by enforcing standards across environments.
Real use: pushing a standardized firewall policy to every branch device or detecting configuration drift and fixing it automatically.
Q3. What are common tools for network automation?
Common network automation tools help teams push configs, collect data, and validate states. The tools depend on device vendors, workflows, and team skill levels. Popular choices include Ansible, Python libraries, and controller APIs.
Example: Nornir runs parallel tasks across devices quickly and Terraform provisions cloud networking and security groups reliably.
Q4. Which programming language is best for network automation?
Python is the best starting language for network automation in most teams today. It is easy to read and has strong networking libraries. Python also integrates well with APIs, YAML, and JSON data formats.
Example: Netmiko, a Python library can automate CLI tasks through SSH securely.
Q5. What is an API in network automation?
An API is a structured way to interact with devices and network platforms. It lets software request information or applies configuration changes safely. APIs reduce dependence on fragile text-based CLI parsing methods.
Common API uses:
- Collect device data
- Change configuration
- Update security policies
- Monitor network health
Example: A script queries interface status and error counters using API calls.
Q6. What is REST API?
A REST API is a web-style API using standard HTTP methods for actions. It commonly uses GET to read data and POST to create resources. REST APIs are widely used in controllers and network management platforms.
| Method | Meaning | Use Case |
| GET | Read data | Check device status |
| POST | Create data | Add a new object |
| PUT/PATCH | Update data | Change a setting |
| DELETE | Remove data | Delete a rule |
Example: GET retrieves device list from an SD-WAN controller and POST pushes a new configuration template to multiple sites.
Q7. What is JSON in network automation?
JSON is a data format used to send and receive structured information in automation. Many network APIs return JSON because it is compact and predictable. Scripts parse JSON to extract values like interfaces, routes, and device health.
Example: read “hostname” and “serial” fields from a controller response and also send JSON payload to create a network policy object.
Q8. What is YAML in network automation?
YAML is a human-friendly data format used in automation configuration and templates. It is popular because it is readable and supports nested structures easily. Tools like Ansible rely heavily on YAML for playbooks and variables.
Example: A YAML playbook can tell Ansible to create a VLAN on all switches.
Q9. What is Ansible in network automation?
Ansible is an automation tool that runs tasks against network devices and systems. It is agentless, so devices usually need no extra software installed. Ansible uses modules to configure vendors through SSH or APIs.
Network engineers like Ansible for Network automation because:
- Easy to read
- Uses YAML
- No agent required
- Good for repeated configuration tasks
Example: You can apply consistent SNMP and syslog settings across all switches and also collect interface details and generate a compliance report automatically.
Q10. What is an Ansible playbook?
An Ansible playbook is a YAML file describing steps to automate tasks. It defines target hosts, tasks, variables, and expected end results. Playbooks help teams standardize changes and repeat them safely.
Common playbook tasks are:
- Take device backups
- Create VLANs
- Add users
- Push configuration changes
Q11. What is an inventory file in Ansible?
An inventory file is a list of devices Ansible should manage and target. It can group devices by role, location, or model for safer deployments. Inventory also stores connection details and sometimes host variables.
Example: With Ansible inventory, you can group devices into core, distribution, and access layers for staged rollouts and also separate regions like Delhi and Mumbai to reduce blast radius.
Q12. What is idempotency in network automation?
Idempotency means running automation repeatedly without changing the correct final state. If the device already matches the desired configuration, nothing changes. This prevents duplicate commands and reduces unintended disruptions.
Idempotency is important because it:
- Makes automation safer
- Avoids duplicate changes
- Helps in production networks
- Gives predictable results
Q13. What is Infrastructure as Code?
Infrastructure as Code or IaC means defining infrastructure using files instead of manual clicks. These files can be versioned, reviewed, tested, and rolled back easily. IaC helps networks become consistent across sites and environments.
Example: A team can store router configuration templates in Git and check every change before applying it.
Q14. What is network programmability?
Network programmability means controlling network behaviour through models and software. It is a combination of the use of APIs and data models as well as automation frameworks working together. Programmability allows dynamic changes in response to policies and real-time data.
Example: An API-driven script adjusts QoS settings for critical applications. Programmability goes beyond scripts by using structured interfaces and consistent models.
Q15. What is SDN?
SDN stands for Software Defined Networking and centralizes network control decisions. It separates the control plane from the data plane on devices. A controller defines policies and devices enforce forwarding behavior.
Example: SD-WAN controllers push routing policies to branch devices centrally.
Q16. What is the difference between SDN and network automation?
SDN is a network architecture where control logic is centralized in software controllers. Network automation is a method that automates tasks, even on traditional networks.
Automation can use CLI, scripts, or APIs without changing architecture. SDN usually requires controller-based design and compatible infrastructure.
Example: SDN sets forwarding policies centrally across fabric devices and Automation pushes standardized configs to existing routers.
Q17. What is NETCONF?
NETCONF is a protocol for the management of device configuration in a structured manner. It can predictively respond to commands such as edit, get, and commit. NETCONF reduces reliance on brittle text scraping from CLI outputs.
NETCONF is often used with:
- YANG models
- XML data
- Programmable network devices
Example: An automation tool can use NETCONF to change an interface description on a router.
Q18. What is YANG?
YANG is a data modeling language describing network configuration and operational data. It defines a structured schema, so tools know what fields exist. YANG models help validate configs and reduce vendor-specific command differences.
Example: A YANG model can define interface name, IP address, speed, status, and description. This helps automation tools work more clearly with network devices.
Q19. What is RESTCONF?
RESTCONF is a REST-based way to access YANG-modeled configuration and state data. It uses HTTP methods like GET, PUT, PATCH, and DELETE. RESTCONF is simpler for web developers than NETCONF in many cases.
RESTCONF is useful when you want API-based network automation with structured device data.
Q20. What is Zero Touch Provisioning?
Zero Touch Provisioning lets a new device to configure itself using only a minimum of human effort. The device starts, receives an IP address and then downloads the software and configs automatically. ZTP helps reduce the time needed to deploy and guarantees consistent base configuration.
Example: A branch router auto-registers with SD-WAN controller after first boot. ZTP is a common Day 1 automation approach.
Q21. What are Day 0, Day 1, and Day 2 automation tasks?
Day 0 tasks cover planning, standards, and templates before deployment begin.
Day 1 tasks cover installation, onboarding, and initial configuration of devices.
Day 2 tasks cover operations, monitoring, patching, and ongoing optimization. Example:
Example: Day 0 builds golden configs and IP plans for every site. Day 1 performs ZTP, baseline setup, and controller registration. Day 2 runs backups, compliance checks, and drift remediation regularly.
Q22. How does automation help in network troubleshooting?
Automation captures evidence in a fast and consistent manner to speed up troubleshooting. It can perform the same checks on the devices and will show up anomalies instantly. This saves time to repetitive commands and manual comparison.
Example: With automation, you can gather interface errors and compares them against baselines. Auto-generating incident reports from collected logs and metrics is also possible.
Q23. What are the risks of network automation?
The more changes that are made to multiple devices at once, the greater the risk of network automation. If the wrong template, a bad variable or a logic bug occurs, it can lead to widespread outages. In addition, there are security risks if credentials and secrets are mishandled.
Example: If an update to the ACL is incorrect, it can restrict traffic for an entire region, or if a script fails to send, it can send the wrong VLAN mapping to many access switches.
Minimize impact through approvals, testing, and staged deployments.
Q24. What are best practices for network automation?
Automation is reliable, safe, and easy to maintain over time by following best practices. You can:
- Implement version control, testing, approval, and rollback of all changes.
- Try to begin with low-level workflows and scale up when workflows run without any problems.
- Use vaults to store secrets not code or plain files.
- Also, document templates and use a consistent naming across devices and automation scripts.
Q25. What skills are required for a network automation engineer?
A network automation engineer should have strong networking fundamentals along with an automation mindset. Comprehensive knowledge of routing, switching, addressing, and security is required. The basics of Python, APIs, and data formats such as JSON/YAML are also required. Tools skills like Ansible, Git, and basic CI/CD concepts for safe delivery.
Ready to Build Real Network Automation Skills? If you want hands-on experience with Python, Ansible, APIs, and enterprise automation labs, check out the Network Automation Course by PyNet Labs designed for CCNA/CCNP learners and working professionals.
Conclusion
Network automation is now a useful skill for every network engineer. It helps reduce manual work, avoid common mistakes, and manage large networks in a better way. A good engineer should understand networking basics along with Python, Ansible, APIs, JSON, YAML, SDN, NETCONF, RESTCONF, and troubleshooting methods.
The network automation interview question and answers that we have discussed help build a clear base for both beginners and working professionals.
