Note: Still in active development and potentially subject to major changes - keep this in mind when using this.

Netlint

Performs static analysis on network device configuration files.

Linters have long since been a standard way of assessing code quality in the software development world. This project aims to take that idea and apply it to the world of network device configuration files.

Find the latest copy of the documentation here.

Try out the web version here (your configuration file input is not saved or shared with anyone).

Example usage

Below is an example of how to use this based on one of the faulty test configurations (executed from the project root):

$  netlint -i tests/configurations/cisco_ios/faulty.conf
IOS101 Plaintext user passwords in configuration.
-> username test password ing
IOS102 HTTP server not disabled
-> ip http server
-> ip http secure-server
IOS103 Console line unauthenticated
-> line con 0

Scope

Some potential use cases of netlint are the following:

• Linting network device configurations generated in CI/CD automation pipelines
• Assistance when building out new configurations for both traditional and automated deployment
• Basic security auditing of configuration files
• Validating configuration hygiene such as references to undefined configuration items (e.g. ACLs)

The following things are explicitly not in scope of netlint:

• Correlation of configurations (for example answering the question of whether two BGP neighbors might come up or not)
• Validation of syntactic configuration correctness
• Analysis of network device state that requires connections to the devices such as interface error counters (netlint does however support getting the configuration from the devices with netlint get)

Installation

There are multiple ways of installing this software.

A package is available on PyPI, therefore you can simply install with pip install netlint and then simply run netlint.

If you prefer to install directly from GitHub, here is how you would go about that.

$ git clone https://github.com/Kircheneer/netlint.git
$ git checkout $TAG  # Optionally checkout a specific tag
$ cd netlint
$ pip install .
$ netlint --help
Usage: netlint [OPTIONS] COMMAND [ARGS]...

  Lint network device configuration files.

  [...]