Overview
This lecture provides an introduction to network automation for the CCNA exam, covering the basics of automation benefits, logical network planes, and software-defined networking (SDN).
Network Automation Overview
- Network automation streamlines device management and configuration, reducing manual repetitive tasks.
- Automation is about understanding core concepts for CCNA; hands-on skills are required at higher certification levels.
- Traditional device management is manual and prone to errors, inefficiencies, and configuration drift.
Benefits of Network Automation
- Reduces human error, such as typos, by eliminating manual input.
- Increases scalability; tasks can be performed across many devices quickly.
- Ensures consistent policy and configuration compliance across all devices.
- Decreases operating expenses (OpEx) by saving time and effort.
Logical Planes of Network Functions
- Data plane (Forwarding plane): Handles the actual forwarding of user data packets through hardware like ASICs and stores tables in TCAM.
- Control plane: Builds and maintains routing and MAC address tables, using protocols like OSPF, STP, and ARP, and runs on the CPU.
- Management plane: Used for device management and monitoring with protocols like SSH, SNMP, Syslog, and NTP, processed by the CPU.
Software-Defined Networking (SDN)
- SDN centralizes the control plane into a controller application, unlike distributed traditional networks.
- The controller uses southbound interfaces (SBIs) to communicate with and manage network devices.
- Examples of SBIs include OpenFlow, OpFlex, onePK, and NETCONF.
- The northbound interface (NBI), such as a REST API, allows apps to interact with the controller.
- NBIs typically return data in structured formats like JSON or XML for easy programmatic use.
Automation in Traditional Networks vs SDN
- Traditional automation can use scripts (e.g., Python) to push configurations and scrape output.
- SDN provides a network-wide view and easy programmatic access to information, reducing the need for custom scripts.
- SDN enhances automation through controller APIs and structured data.
Key Terms & Definitions
- Automation — Use of scripts or tools to perform network tasks automatically.
- Data Plane — Network function responsible for forwarding traffic at high speeds.
- Control Plane — Controls routing and decision-making logic for forwarding.
- Management Plane — Handles device management and monitoring.
- ASIC — Specialized hardware chip for fast data forwarding.
- TCAM — High-speed memory used for rapid lookups in network devices.
- SDN — Architecture that centralizes the control plane for easier automation.
- Controller — Centralized software managing control functions in SDN.
- SBI (Southbound Interface) — Protocol/API for communication between SDN controller and devices.
- NBI (Northbound Interface) — API for apps to communicate with the SDN controller.
- API — Interface allowing software programs to communicate and exchange data.
Action Items / Next Steps
- Review key SBIs: OpenFlow, OpFlex, onePK, NETCONF.
- Prepare for detailed study on data serialization formats (JSON, XML) in the next lecture.
- Complete any assigned quizzes or practice questions.