Chapter 2 Why Automate the Network?

source of truth can be referenced using pull requests and commit information to find the last changes and how they relate to outages. The automated documentation can be used to confirm configurations and key information about devices without the need to connect to any device. Ansible can also be used to rapidly deploy a fix to the enterprise if a flaw is found or a change to multiple devices is required to resolve an issue. This method has the benefit of being included in the source of truth and master branch for future reference.

Resources Network staff may not adapt to change as rapidly as other IT disciplines, mainly because the way networks are managed has not changed all that much over the past 30 years. However, network staff should always be looking for the most effective way to manage the network. Most will fully embrace this new methodology because of the power it unlocks and how much easier it will make their lives in the long run. Once the transition has been made resources can be reallocated to more strategic projects. Ultimately, a stronger workforce emerges with modern, diverse problem-solving skills, software development principals and basic coding abilities. There may not be a place for the CLI warrior in the next-generation network.

Cost

Capital expenditure savings can be achieved using network automation. Instead of large, expensive, appliance-based NMS solutions or agent-based software solutions, build an in-house solution custom fit to the organization’s needs. Even larger savings can be realized in operational expenditures. Time spent in manual CLI device-to-device configurations or information gathering is eliminated. Overtime incurred for after hour changes is drastically reduced. Changes that took hours now take minutes. Large disruptive changes take significantly less time and effort because the power of the automation engine is orchestrating and delivering the solution. These are huge benefits to any organization and demonstrates an immediate ROI. It is hard to put a price on having a central repository acting as a source of truth for the network.

Provisioning One capability to consider, now that configuration management is automated, is device provisioning. Provisioning new devices is a repeatable, one-time task and an ideal candidate for automation. Some “zero-touch” provisioning solutions exist as part of NMS solutions however they are often complex, and mileage may vary. Using a homegrown automation solution, several options are available to automate provisioning, however, these options still require one or two touches to the device.

An operator can generate an automated configuration using data models, dynamic templates, and the Ansible framework. Then they transfer the generated golden configuration to a USB drive and connect to the console replacing the start-up configuration of the device with the generated, templated, configuration.

Alternatively, the operator can use the console to configure the device with bare minimum requirements to be delivered in place. Connect the device to the network and push the generated configuration over SSH using an Ansible playbook. The device requires some initial configuration for reachability including a management IP address, SSH access over VTY lines, and the appropriate uplink interfaces configured before delivering on-site. Once installed and connected, the remaining golden