What is the main focus of blog #4 in the CCIE Automation journey?

Blog #4 focuses on automating network discovery and reporting using Python and Ansible, replacing manual discovery and documentation tasks with a fully automated workflow.

What does the Python discovery script do?

The script scans a subnet for devices with SSH enabled, authenticates using Netmiko, detects the device platform (IOS or NX-OS), builds an Ansible inventory, and triggers an Ansible playbook for further data collection.

How is Ansible used in this solution?

Ansible is used to gather system and neighbor information from the discovered devices, including hostname, hardware model, software version, and CDP/LLDP neighbors.

How are the results presented?

The output is a single consolidated HTML report generated using a Jinja2 template, presenting all discovered devices in tabular form with expandable sections for neighbor details.

Why is this workflow valuable for network engineers?

Network discovery and documentation are commonly performed manually. Automating these tasks improves accuracy, reduces human error, and saves significant time.

How does this build on previous blogs in the series?

The solution integrates into the existing Nautix architecture and combines Python, Ansible, and previously built services into a cohesive automation pipeline.

What is planned next in the CCIE Automation series?

Blog #5 will focus on pyATS, including automated network health testing, Genie parsers, and test job development.

Sicra helps organizations modernize network operations through automation, standardization, and secure architectures—from advisory services to hands-on implementation. Read more about "Network" here > Read more about "Secure software development" here > Read more about "Cloud (Azure, AWS, Google)" here > Read more about "Project management" here >

Blog

04.09.2025

min read

[My journey to CCIE Automation #4] Automating network discovery and reports with Python and Ansible

In blog #4 of the CCIE Automation journey, network discovery and reporting are automated using Python and Ansible. By combining subnet scanning, fact gathering, and template-based reporting, a complete workflow is built that produces a clear HTML report of the network.

<span id="hs_cos_wrapper_name" class="hs_cos_wrapper hs_cos_wrapper_meta_field hs_cos_wrapper_type_text" style="" data-hs-cos-general-type="meta_field" data-hs-cos-type="text" >[My journey to CCIE Automation #4] Automating network discovery and reports with Python and Ansible</span>

(Denne artikkelen var tidligere en del av Bluetree.no. Siden Sicra og Bluetree har slått seg sammen, er nå innhold fra Bluetree overført til Sicra.)

[My journey to CCIE Automation #4] Automating network discovery and reports with Python and Ansible is part of a series following my CCIE Automation journey. In the previous post, I worked with NETCONF and an Orchestration API. In this post, I focus on automating network discovery and reporting with Python and Ansible.

Blog #4

After NETCONF in blog #3, I wanted to pick something network engineers often do manually — discovering devices, collecting facts, and documenting neighbors — and automate it with Python and Ansible.

The project in this post is network discovery and reports. A small workflow that scans a subnet, discovers devices, runs commands, and generates a nice HTML report.

What I built

1. Python Discovery script

A Python CLICK app (network_discovery.py) that:

Scans a subnet for devices with SSH open.
Logs in with username/password using Netmiko.
Detects whether the device runs IOS or NX-OS.
Builds an Ansible inventory file with the correct ansible_network_os.
Executes an Ansible playbook that will gather facts about the discovered hosts:
- Hostname
- Hardware model
- Software version
- CDP/LLDP
Then generate a HTML report listing the discovered hosts and the facts gathered.

Sample from script (see repo for full details:

image-png-Sep-05-2025-08-20-04-0999-AM

2. Ansible playbook

The playbook (gather_device_facts.yml) runs against the discovered hosts and gathers system + neighbor info and generates a HTML report.

Sample of gathering data from the discovered hosts:

image-png-Sep-05-2025-08-28-20-1232-AM

Right now it only supports Cisco IOS and Nexus, but it can easily be extended to other platforms.

3. HTML Raport

Instead of raw CLI output, I render a single HTML report with a Jinja2 template. Every device is listed in a table, with expandable CDP/LLDP sections.

Sample from jinja2 template:

image-png-Sep-05-2025-08-31-31-9614-AM

4. The result – View the HTML report

You get a list of all hosts discovered with a column for:

IP
Hostname
Model
Version
OS

At the end you get a list of all CDP and/or LLDP neighbors for each device discovered.

image-png-Sep-05-2025-08-35-48-4072-AM

How to run

Se README i GitLab-repositoriet.

Service Interactions update

I've updated the new use case to the Nautix diagram.

image-png-Sep-05-2025-08-48-46-4010-AM

What's next

In blog #5 I will focus on working with pyATS:

Blueprint item 3.3 Modify and troubleshoot an automated test by using pyATS to meet requirements

3.3.a Create a testbed file for connecting to Cisco IOS, IOS XE, or NX-OS devices

3.3.b Gather current configuration and operational state from devices using the Genie parsers and models included with pyATS

3.3.c Develop and execute test jobs and scripts using AEtest to verify network health

Useful links

Blog series

Need Assistance?

We are happy to have a non-binding conversation.

Explore more