netmiko Documentation

Netmiko supports SSH key-based authentication and the use of local SSH configuration files.

• SSH Keys: Set use_keys=True and provide the path to your private key in key_file within the device dictionary.
• SSH Config: Provide the path to your SSH config file using the ssh_config_file key in the device dictionary.

To install the Netmiko library, use the standard Python package manager, pip.

$ pip install netmiko

To run the local test suite, you must first initialize the test configuration files by copying the provided examples in the netmiko/tests/etc directory.

cd ./netmiko/tests/etc  
cp test_devices.yml.example test_devices.yml  
cp responses.yml.example responses.yml  
cp commands.yml.example commands.yml  

To apply configuration changes, use send_config_set(commands) for a list of commands or send_config_from_file(filename) to read commands from a file. Netmiko automatically handles entering and exiting configuration mode. After applying changes, remember to save the configuration using the platform-appropriate method (e.g., save_config() for most platforms, or commit() for Cisco-XR, Juniper-Junos, and Palo Alto).

# Applying a list of commands
commands = ["logging buffered 100000"]
with ConnectHandler(**device) as net_connect:
    output = net_connect.send_config_set(commands)
    output += net_connect.save_config()

# Applying from a file
with ConnectHandler(**device) as net_connect:
    output = net_connect.send_config_from_file("config_changes.txt")
    output += net_connect.save_config()

After copying the example files, you must customize them to define your test parameters:

1. Edit test_devices.yml

Select the device_types you wish to test. For each device, provide:

• ip
• username
• password
• secret (optional)

2. Edit responses.yml

For each device_type defined in your devices file, update the following fields to match your test device's behavior:

• base_prompt
• router_prompt
• enable_prompt
• interface_ip

If a command triggers a prompt that requires a delay-based response (e.g., a confirmation), use send_command_timing(). This method relies on timing rather than pattern matching. You can use strip_prompt=False and strip_command=False to preserve the full interaction in the output.

# Example of handling a 'confirm' prompt via timing
output = net_connect.send_command_timing(
    command_string="del flash:/test3.txt",
    strip_prompt=False,
    strip_command=False
)
if "confirm" in output:
    output += net_connect.send_command_timing(
        command_string="y",
        strip_prompt=False,
        strip_command=False
    )

To debug communications, you can enable Netmiko logging to capture all reads and writes of the communications channel. This requires configuring the standard Python logging module with a DEBUG level and targeting the netmiko logger.

import logging
logging.basicConfig(filename='test.log', level=logging.DEBUG)
logger = logging.getLogger("netmiko")

When encryption is enabled in the __meta__ section, Netmiko automatically decrypts any field that starts with the __encrypt__ prefix.

Example format in YAML:

password: >
  __encrypt__<encrypted_payload_here>

Netmiko reads the encryption key from the NETMIKO_TOOLS_KEY environment variable. This key must be a secure, randomly-generated value appropriate for your chosen encryption type (e.g., a Fernet key for fernet encryption).

export NETMIKO_TOOLS_KEY="your-secure-key-here"

Navigate to the netmiko/tests directory to run the test suite. You must specify a --test_device flag, which corresponds to the device name defined in both test_devices.yml and responses.yml.

Available test scripts:

• test_netmiko_show.py
• test_netmiko_config.py
• test_netmiko_commit.py (Note: currently only supported for Juniper and IOS-XR)

cd ./netmiko/tests

# Example: testing show commands on a cisco881 device
py.test -v test_netmiko_show.py --test_device cisco881  

# Example: testing configuration commands on a cisco881 device
py.test -v test_netmiko_config.py --test_device cisco881