Understanding the Connection Between YANG, NETCONF, RESTCONF, and CCNP Enterprise
In February 2020, Cisco introduced a revamped certification path, marking a significant shift in how network professionals are prepared for modern network demands. Among the most notable updates was the integration of network automation and programmability, which is now at the heart of the new certification offerings. This change reflects the growing role of automation in managing networks, especially as network complexity increases and the industry shifts toward more scalable, flexible, and efficient systems.
The updated certifications are designed to meet the demands of today’s networks, which are more dynamic and require greater levels of automation and integration. The goal of these changes is not just to validate foundational networking knowledge but also to equip professionals with the skills necessary to manage programmable networks effectively.
The CCNP Enterprise certification is central to this new direction, reflecting Cisco’s recognition of the importance of automation in network management. Among the various updates, protocols such as YANG, NETCONF, and RESTCONF have become fundamental for network programmability, and understanding these protocols is now crucial for success in the CCNP Enterprise certification.
The shift toward automation also underscores the increasing importance of technologies like Python, Ansible, and other tools that streamline the configuration and management of devices across an enterprise network. Network engineers are expected to have hands-on experience with these tools and be familiar with the principles of automation to improve operational efficiency, reduce human error, and ensure better scalability.
This article will explore how the key protocols YANG, NETCONF, and RESTCONF are integrated into the CCNP Enterprise certification path, particularly in terms of network automation. These protocols are essential for modern network programmability, and they form the backbone of the automation efforts required for managing today’s complex network infrastructures.
The transformation of Cisco’s certification structure has been largely driven by the increasing complexity of modern networks and the growing need for automation in network management. With more devices, more traffic, and more demands for reliability, network automation has become a necessity rather than a luxury. In this context, automation becomes a central focus for those pursuing the CCNP Enterprise certification.
The new certification path for CCNP Enterprise includes two key exams: the core exam (350-401 ENCOR) and a concentration exam that targets specific areas of expertise. The core exam serves as the foundation, covering a broad range of networking topics, while the concentration exam allows candidates to focus on their chosen specialization, such as advanced routing and switching or automation.
The inclusion of automation as a key topic in the CCNP certification marks a major shift in how network engineers approach network management. Instead of focusing solely on manual configuration tasks, network professionals must now demonstrate the ability to automate and program their devices to improve efficiency and reduce the risk of human error.
As part of the core exam, 15% of the content now focuses specifically on automation. This covers a wide range of tools and concepts, including Python scripting, network automation platforms like Ansible, and protocols like YANG, NETCONF, and RESTCONF. Candidates are expected to understand how to apply automation to real-world networking tasks, such as configuring devices, monitoring network performance, and troubleshooting issues.
YANG, NETCONF, and RESTCONF are pivotal in the context of network automation. These protocols and tools allow network devices to be configured and managed programmatically, enabling network engineers to automate tasks that would otherwise be time-consuming and error-prone if done manually.
These protocols have become integral to the modern network engineer’s toolkit. They not only allow for configuration management but also enable efficient monitoring and troubleshooting, making them essential in network automation workflows. Understanding these protocols is vital for those preparing for the CCNP Enterprise certification, particularly in areas like automation and programmability.
Network automation is increasingly becoming a central part of network management. The 350-401 ENCOR exam tests candidates on their ability to automate network devices and manage network configurations using a variety of tools and protocols. Among the most important tools are Python and automation platforms like Ansible, which are often used in conjunction with protocols like YANG, NETCONF, and RESTCONF.
Python plays a central role in network automation due to its simplicity and the wide range of libraries available for interacting with network devices. For instance, Python’s ncclient library is used to interact with NETCONF-enabled devices, while the requests library is used to send HTTP requests to devices configured with RESTCONF. These libraries simplify the process of automating network tasks, allowing engineers to write scripts that can automate everything from configuration changes to monitoring and troubleshooting.
Python’s role in network automation cannot be overstated. Its simple syntax and robust ecosystem of libraries make it the ideal language for automating a wide variety of network management tasks. In the CCNP Enterprise exam, candidates must be familiar with how to write Python scripts that automate tasks like configuration changes, device monitoring, and troubleshooting.
Python libraries such as ncclient (for NETCONF) and requests (for RESTCONF) enable seamless interaction with network devices. Engineers are expected to understand how to create and manipulate Python scripts to automate tasks such as pushing configuration changes, retrieving network statistics, and even handling common errors that may arise during automation tasks.
In addition to Python, other tools like Ansible are also a key part of network automation. Ansible, for example, allows engineers to automate the configuration of network devices using simple, human-readable YAML files known as playbooks. These playbooks define a series of tasks to be executed on one or more devices, making it easier to manage complex network environments.
Ansible has become one of the most widely used tools for network automation, thanks to its agentless architecture and easy-to-read YAML syntax. Ansible allows network engineers to automate repetitive tasks such as device configuration, monitoring, and software updates without the need to install agents on each network device. This makes it particularly useful in large-scale environments where managing configurations manually can be both time-consuming and prone to errors.
With Ansible, tasks are defined in playbooks, which specify the actions to be performed on one or more devices. For example, a playbook can be used to configure VLANs, backup device configurations, or gather device facts like model numbers or software versions. These playbooks can be executed across large networks, ensuring that configurations are applied consistently and efficiently.
Automation platforms like Ansible and Python complement YANG, NETCONF, and RESTCONF by enabling engineers to automate network management tasks in a structured and consistent manner. They help bridge the gap between programming and network management, allowing engineers to implement automation in both simple and complex network environments.
In this section, we will take a deep dive into the key protocols and tools that are integral to network automation, focusing on YANG, NETCONF, and RESTCONF. These protocols not only provide the foundation for network programmability but also ensure that automation tasks can be performed efficiently and in a standardized manner. As part of the CCNP Enterprise certification, it is essential to understand how these protocols work together to facilitate network automation.
YANG, which stands for “Yet Another Next Generation,” is a data modeling language that plays a pivotal role in network automation. It is used to define the structure of configuration and operational data that is exchanged between network devices and automation tools. YANG enables the creation of consistent, vendor-neutral data models, which are critical in automating network management tasks.
YANG models define how data should be represented and structured. They allow network engineers to create configurations that are easily understood and manipulated by automation tools. The main advantage of YANG lies in its ability to model network devices and services in a way that is independent of the underlying device or vendor. This standardization is crucial for large-scale networks that may contain devices from multiple vendors, as it provides a consistent way to interact with and configure them.
A YANG model typically consists of a hierarchical structure, with containers, leaf nodes, and lists representing different configuration parameters. For example, a YANG model for a network interface might define the interface name, type, IP address, and other parameters in a standardized format. This allows automation tools to interact with devices in a consistent way, regardless of the specific hardware or software being used.
Understanding YANG is essential for CCNP candidates, as it forms the foundation for many of the automation protocols used in network programmability. Engineers are expected to know how to interpret YANG model trees, understand the difference between YANG models from different sources (such as IETF, OpenConfig, and native models), and map YANG data models to device configurations.
NETCONF, short for Network Configuration Protocol, is a powerful protocol designed to manage network devices in a structured and automated way. NETCONF works alongside YANG to allow for configuration management, state data retrieval, and device monitoring. It is a mature and feature-rich protocol that has been widely adopted in network automation, particularly in large-scale enterprise environments.
NETCONF operates over a secure transport protocol, typically SSH, and uses XML for data encoding. The protocol supports several key operations, including:
One of the key features of NETCONF is its ability to perform atomic transactions, ensuring that configuration changes are applied consistently and reliably. This means that if an error occurs during the configuration process, the changes can be rolled back to their previous state, preventing incomplete or inconsistent configurations.
NETCONF’s use of YANG models to validate and filter configuration data is another critical feature. YANG provides a structured way to define how configuration data should be represented, and NETCONF leverages these models to ensure that the data being sent to devices is valid and properly structured.
For example, a NETCONF operation might use a YANG model to ensure that a VLAN configuration is correct before applying it to a switch. This helps prevent errors and ensures that devices are configured according to a standardized model.
RESTCONF is a network management protocol that is built on the principles of REST (Representational State Transfer). It provides a simpler and more flexible alternative to NETCONF, making it particularly appealing for modern network environments that rely on HTTP and web-based tools. Unlike NETCONF, which uses XML for data encoding, RESTCONF supports both XML and JSON, with JSON being the preferred format due to its simplicity and readability.
RESTCONF operates over standard HTTP methods such as GET, POST, PUT, and DELETE, which makes it compatible with a wide range of web technologies. These methods are used to interact with network devices and perform various operations, such as retrieving data, creating configurations, and updating existing configurations.
The key operations in RESTCONF include:
One of the main advantages of RESTCONF is its ease of integration with web technologies and modern cloud-native platforms. Since it operates over HTTP and uses JSON as its primary data format, it is simple to integrate RESTCONF into existing web-based automation workflows. This makes it an ideal choice for network engineers who are already familiar with RESTful APIs and web development concepts.
RESTCONF’s lightweight nature and use of HTTP make it a popular choice for managing devices in environments that require frequent, real-time interactions. For example, RESTCONF is often used in cloud-based environments where network configurations are frequently updated and need to be automated.
While both NETCONF and RESTCONF serve similar purposes—network management and automation—they differ significantly in terms of their complexity, functionality, and use cases. The choice between NETCONF and RESTCONF depends largely on the specific needs of the network environment and the level of control required.
NETCONF is the more feature-rich protocol, offering advanced configuration management capabilities such as atomic transactions, rollback, and detailed configuration validation using YANG models. It is particularly well-suited for large-scale enterprise environments where robust configuration management features are required, such as service provider networks and data centers. NETCONF’s ability to perform complex configurations with high reliability makes it the preferred choice for scenarios where configuration consistency and security are critical.
RESTCONF, on the other hand, is a simpler, more lightweight protocol that is easier to integrate with web-based tools and cloud-native platforms. It is ideal for environments that rely on API-driven management and where ease of use and integration with modern web technologies are priorities. RESTCONF is particularly useful for network automation in environments where the complexity of NETCONF is not required, or where quick, simple interactions are more important than advanced configuration management features.
For network engineers preparing for the CCNP Enterprise certification, it is essential to understand both protocols and know when to use each one. While NETCONF may be better suited for complex, high-security environments, RESTCONF is more appropriate for simpler, web-based automation workflows.
Together, YANG, NETCONF, and RESTCONF form the core framework for network automation in modern enterprise environments. YANG provides the data modeling language necessary for defining consistent, vendor-neutral data structures, while NETCONF and RESTCONF serve as the protocols that enable the automation of network configuration and management.
In a typical network automation workflow, YANG models define the structure of the data being exchanged, whether it is for configuration, operational status, or performance monitoring. NETCONF or RESTCONF is then used to send and receive data to and from network devices, ensuring that configuration changes are applied consistently and efficiently.
For example, an automation workflow might involve using YANG to define the configuration of a network interface on a router, then using NETCONF to apply the configuration to the device. Alternatively, a network engineer might use RESTCONF to retrieve interface statistics in real time, analyze the data, and take action to address any issues that arise.
The integration of these protocols into the CCNP Enterprise certification path reflects the growing importance of automation in network management. Aspiring network engineers must not only understand how to work with these protocols but also be able to apply them in real-world scenarios to improve the efficiency, scalability, and reliability of their networks.
In the previous sections, we’ve covered the foundational concepts of YANG, NETCONF, and RESTCONF, as well as their roles in network automation. Now, let’s explore how these protocols are applied in real-world scenarios and how network engineers can leverage them to improve network management, configuration, monitoring, and troubleshooting. By understanding the practical applications of these protocols, CCNP candidates can better prepare for automation tasks that they may face during the certification exams and in their professional careers.
One of the most significant advantages of using NETCONF in network automation is its ability to manage large-scale network configurations efficiently. NETCONF, with its ability to perform atomic transactions and rollback capabilities, is ideal for environments where configuration consistency and reliability are paramount.
Consider a scenario where a network engineer is tasked with applying the same configuration change across hundreds of routers in a large enterprise network. Manual configuration of each device via the command-line interface (CLI) would be time-consuming and prone to human error.
Using NETCONF, this task can be automated by writing a Python script that interacts with multiple routers simultaneously. The script can send configuration data encoded in XML to each device, ensuring that the changes are applied consistently across the entire network.
The process could look as follows:
from ncclient import manager
# Connect to the network device using NETCONF
With the manager.connect(
host=”192.168.1.1″,
port=830,
username “admin”,
password “admin”,
hostkey_verify=False
) as m:
# Define the configuration changes
interface_config = “””
<config>
<interfaces xmlns=” urn:ietf:params:xml:ns:yang:ietf-interfaces”>
<interface>
<name>GigabitEthernet1</name>
<description>Configured via NETCONF</description>
</interface>
</interfaces>
</config>
“””
# Apply the configuration
response = m.edit_config(target=”running”, config=interface_config)
print(response)
In this example, the Python script connects to the device, applies the configuration, and prints the response. NETCONF automates the process, making it faster and more reliable than manual configuration.
While NETCONF is ideal for configuration management, RESTCONF is often used for real-time monitoring and data retrieval. Its ability to work over HTTP and support JSON data makes it well-suited for environments where data needs to be collected, processed, and visualized quickly.
Consider a scenario where a network engineer needs to monitor the status of network interfaces in a large data center. Rather than logging into each device manually or using SNMP, the engineer can use RESTCONF to collect operational data about the interfaces in real-time.
Using RESTCONF, the engineer can query network devices for interface statistics such as operational status, traffic volume, and error rates. The data returned in JSON format can then be parsed and visualized using tools like Grafana or integrated into an automated alerting system.
import requests
from requests. auth import HTTPBasicAuth
import json
# RESTCONF URL to get interface status
url = “https://192.168.1.1/restconf/data/ietf-interfaces:interfaces”
# Senda GET request to retrieve the interface data
response = requests.get(url, auth=HTTPBasicAuth(“admin”, “admin”))
# Parse the JSON response
data = response.json()
# Extract interface status and print it
for interface in data[“ietf-interfaces:interface”]:
print(f”Interface {interface[‘name’]} is {interface[‘enabled’]}”)
print(f”Description: {interface.get(‘description’, ‘No description available’)}”)
In this example, the script queries the device for interface data using the RESTCONF API and prints the status of each interface. RESTCONF’s use of JSON makes it easy to parse and process the data, allowing for real-time monitoring of network interfaces.
While NETCONF is ideal for configuration management, RESTCONF’s simplicity and integration with web-based systems make it an excellent choice for automated device provisioning in a network automation workflow. Ansible, a popular automation tool, can be used in conjunction with RESTCONF to provision and configure devices across a large network.
When a new switch is added to the network, it needs to be provisioned with the appropriate VLANs, IP addresses, and other settings. Rather than manually configuring each new device, Ansible can automate this process, using RESTCONF to interact with the devices’ APIs.
Ansible playbooks can be written to configure the new devices by sending HTTP requests to the devices’ RESTCONF endpoints. These playbooks can be parameterized to configure devices based on variables such as device type, location, and configuration requirements.
—
– name: Provision a new switch
hosts: switches
gather_facts: no
tasks:
– name: Create VLAN on the switch
uri:
url: “https://{{ inventory_hostname }}/restconf/data/ietf-interfaces:interfaces”
method: PUT
headers:
Content-Type: “application/yang-data+json”
Accept: “application/yang-data+json”
body: |
{
“interface”: {
“name”: “GigabitEthernet1”,
“description”: “Provisioned via Ansible”,
“enabled”: true
}
}
body_format: json
status_code: 200
In this example, the Ansible playbook sends a PUT request to the RESTCONF endpoint of the new switch, creating a new interface with the specified configuration. The playbook automates the provisioning process, ensuring that all switches are configured consistently and accurately.
YANG, NETCONF, and RESTCONF are also valuable tools for troubleshooting and configuration validation. By using these protocols, network engineers can quickly identify configuration errors or operational issues, reducing downtime and improving network reliability.
When managing a large network, it’s essential to ensure that devices are configured correctly and consistently. For example, if a network administrator suspects that a VLAN configuration is incorrect, they can use NETCONF to retrieve the configuration from multiple switches and validate it against a predefined YANG model.
This process not only automates configuration validation but also ensures that the network is running as expected, reducing the chances of human error and ensuring consistent configurations across the network.
In this final section, we will focus on the preparation strategies and practical steps required for success in the CCNP Enterprise certification, particularly the automation and programmability aspects covered in the exam. We will delve into key resources, strategies, and best practices for mastering the skills needed for automating network management using YANG, NETCONF, RESTCONF, Python, and other relevant tools. Additionally, we’ll discuss how to develop hands-on experience and leverage lab environments to reinforce your learning.
The CCNP Enterprise certification is structured to ensure that network professionals are proficient in the most up-to-date network management practices. Network automation has become a core focus in the certification, especially with the shift toward software-defined networking (SDN), cloud integration, and the increasing need for network programmability. In particular, the 350-401 ENCOR exam, which serves as the foundation for the CCNP Enterprise certification, dedicates a significant portion of its content to automation and programmability.
The key automation topics covered in the exam include:
Python for Network Automation: This section tests your ability to write Python scripts to automate network tasks. Candidates should be familiar with Python syntax, libraries like ncclient and requests, and how to interact with devices using automation protocols such as NETCONF and RESTCONF.
YANG and Model-Driven Telemetry: Understanding YANG models and how to use them in automation workflows is critical. The exam will test your ability to interpret YANG model trees, understand data structures, and apply them to network device configurations. Additionally, knowledge of model-driven telemetry (MDT) is necessary for working with real-time data and monitoring.
NETCONF and RESTCONF Protocols: Both NETCONF and RESTCONF are integral to network automation and configuration management. The exam will test your understanding of how to use these protocols for tasks such as configuration management, data retrieval, and device monitoring.
Ansible for Network Automation: Ansible is another key tool covered in the exam, particularly for its role in automating the configuration of network devices. Candidates must understand how to write Ansible playbooks, use modules like ios_config for Cisco devices, and automate network provisioning and management tasks.
Preparing for the 350-401 ENCOR Exam
The 350-401 ENCOR exam covers a wide range of topics, with automation being a central focus. Here are some strategies for preparing effectively:
Since Python is one of the most widely used programming languages in network automation, it’s essential to have a solid understanding of its core concepts. Focus on:
Use online resources, tutorials, and coding exercises to practice Python scripting. Working on simple automation tasks, such as automating the configuration of a single device or querying network statistics, will help you build confidence.
YANG plays a crucial role in network automation, especially in protocol-driven environments like NETCONF and RESTCONF. Focus on:
Practice using YANG models by working with sample configurations. Cisco provides a collection of YANG models on platforms like GitHub, which you can use to better understand how different types of configuration data are structured.
Familiarize yourself with NETCONF and RESTCONF by practicing with real devices or virtual environments. Use tools like:
By using these tools, you can practice automating real-world scenarios and improve your practical skills in network automation.
Ansible is another powerful tool for automating network management tasks. In preparation for the exam, focus on:
You can write simple playbooks to automate tasks across multiple devices, ensuring consistency and accuracy in your network configurations. Use Ansible’s built-in modules, such as ios_config for Cisco devices, to streamline the configuration process.
One of the most effective ways to reinforce your knowledge and gain hands-on experience is through lab environments. Cisco offers several platforms that simulate real-world network environments and allow you to practice automation tasks without the need for physical hardware.
By leveraging these labs, you can get hands-on practice with Python, NETCONF, RESTCONF, and Ansible in real-world scenarios, which will help you gain the confidence and experience needed to pass the CCNP Enterprise exams.
While exam dumps (collections of past exam questions and answers) should not be your primary resource for studying, practice exams can help you familiarize yourself with the structure of the questions and test your knowledge under exam conditions. Use Cisco practice tests to gauge your understanding of network automation topics, identify areas where you need improvement, and refine your time management strategies.
Focus on understanding the concepts behind the questions rather than memorizing answers. This deeper understanding will help you apply your knowledge to real-world scenarios and ensure long-term retention.
Cisco provides a wealth of official study guides and learning materials designed to help you prepare for the CCNP Enterprise exams. These guides offer detailed coverage of the topics included in the exams and provide useful tips and strategies for tackling each section.
In addition to official Cisco study materials, consider supplementing your learning with other resources:
Troubleshooting is an essential skill in network automation. You should be able to identify common issues that may arise during the automation process and implement effective error handling in your scripts. Whether it’s handling failed network connections, invalid data, or incorrect configurations, having a solid troubleshooting methodology will help you resolve issues quickly and efficiently.
Practice troubleshooting network automation scripts and become familiar with common errors in Python, NETCONF, and RESTCONF. Learn how to handle errors, such as connection timeouts, authentication failures, and invalid responses, in a way that ensures your automation tasks run smoothly.
Preparing for the CCNP Enterprise exam requires a combination of theoretical knowledge, practical experience, and hands-on practice. With a focus on network automation and programmability, it’s essential to develop proficiency with tools like Python, Ansible, NETCONF, RESTCONF, and YANG. By mastering these technologies and integrating them into your network management workflows, you’ll not only be prepared for the exam but also positioned for success in the ever-evolving field of network automation.
The skills you acquire during your preparation will be highly valuable in today’s hybrid, cloud-connected environments, where automation is key to efficient network management. With the right resources, hands-on experience, and study strategies, you’ll be well on your way to achieving the CCNP Enterprise certification and advancing your career in network automation.
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