How Network Engineers Should Use Python?

1. Network Automation and Configuration Management

Python can be used to automate repetitive network configuration tasks across multiple devices. Rather than manually configuring each device, you can write Python scripts to push configurations to routers, switches, and firewalls.

Use Cases:

• Automating VLAN configurations across multiple switches.
• Deploying changes to device configurations (e.g., updating access control lists).
• Automating device backups and firmware updates

2. Network Monitoring and Health Checks

Python can automate the process of monitoring network performance and running health checks. You can use it to collect data from devices and analyze that data for performance issues, such as high CPU usage, packet loss, or abnormal latency.

Use Cases:

• Writing a script to monitor device status (up/down, traffic, errors).
• Automating the collection of device metrics and sending alerts when thresholds are breached.
• Polling SNMP data to monitor bandwidth usage.

3. Network Data Parsing and Log Analysis

Python can help network engineers parse and analyze large volumes of network logs or traffic data. It can be used to extract insights from syslogs, device logs, or traffic captures.

Use Cases:

• Parsing syslogs to identify specific events (e.g., interface down, BGP flaps).
• Analyzing packet captures to troubleshoot network issues.
• Automating the extraction of data from CLI outputs

4. Network Device Inventory and Auditing

Python can be used to gather information from network devices, such as interfaces, IP addresses, or routing tables, and generate reports. It can also help in device inventory management and auditing for compliance purposes.

Use Cases:

• Pulling device configuration data and saving it as part of an inventory system.
• Verifying that devices comply with security standards (e.g., checking for insecure protocols).
• Gathering network device inventory and tracking changes.

Python Libraries for Network Engineers

1. Netmiko: A multi-vendor Python library that simplifies the process of connecting to network devices via SSH and executing commands. Use Case: Automating network device configuration and gathering device data.
2. Paramiko: A Python library used for making SSH connections to devices, primarily for interacting with network devices using remote commands. Use Case: Securely accessing devices and executing commands or scripts remotely.
3. NAPALM: A multi-vendor Python library for interacting with network devices via different protocols (SSH, NETCONF, etc.). Use Case: Configuration management and data retrieval from network devices.
4. PySNMP: A Python library for working with SNMP (Simple Network Management Protocol), which is used for monitoring and collecting data from network devices. Use Case: Polling SNMP data for network monitoring and alerts.
5. Scapy: A Python library for packet manipulation and crafting, useful for testing and troubleshooting network protocols. Use Case: Creating, sending, and capturing network packets for network troubleshooting and security testing.
6. Netaddr: A Python library for handling and manipulating network addresses and subnets. Use Case: IP address management, subnet calculations, and CIDR notation manipulation.
7. Ansible (via Python): An open-source tool that uses Python for automating the configuration and management of network devices. Use Case: Automating network deployments and orchestrating device configurations across multiple vendors. Ansible documentation
8. PyYAML: A library to parse and write YAML, which is often used in network automation tools for configuration files (e.g., in Ansible). Use Case: Parsing YAML configuration files for use in automation workflows.
9. TextFSM: A Python library for parsing structured text data, often used to parse CLI command outputs into structured data formats like CSV or JSON. Use Case: Extracting useful data from command outputs like "show" commands.
10. Flask/Django: Python web frameworks that can be used to build dashboards or interfaces for network management.

Use Case:

Building custom web interfaces for monitoring network health or managing network devices