• What is Network Automation ?
• Why Network Automation ?
• Type of Network Automation

Taking avantages of network equipements API

• Program routine or repetitive tasks by using scripts.
  • Python, Shellscripts.
• Streamline network operation with code.
  • What can be defined as code ?
  • Where is the data, where is the logic ?
• Define your infrastructure with code.
  • Build an abstract model of your network.
  • Avoid snow flakes in your network.
• Centralize and version control all network configurations.
  • Git repository should have authority on the network config.
  • Build automatic tests before deploying a config to production.

To simplify the operational architecture

• When devices are configured one by one
  • Error-prone, time-costly, hard to maintain.
  • Each devices is uniquely configured by hand.
  • Partial view of the network.
• When devices are configured by a single program (ex : Ansible)
  • Devices are configured by a code.
  • API majors must be stable over time.
  • Configuration changes are reflected in the code.
  • Global view of the network.

To produce predictible outcomes

• Automated configuration are auto-generated by a program.
  • And code reviewed before applying them to the devices.
  • Configurations is generated from a single program
• Manual configuration are handled by humans on the CLI.
  • Any wrong typing of configuration creates service disruption.
  • The more people work on the configs the less predictible it become.

To operate an Agile network

• Changes coming from the users/applications are accelerating
  • BYOD, Mobility everywhere.
• Deploying new services should take minutes, not days.
  • As with micro-services.

Network automation is not only about configuration management

• Devices provisionning
• Data collection
• Migrations
• Compliance
• Reporting
• Troubleshooting

Device provisionning

• Automate device configuration stored for initial device provisionning
  • First : Create a data file which is vendor-independant, ie the syntax of the configuration does not depend from the vendor.
    • parameters : VLANS, Hostname, NTP, Interface configuration, etc
  • Second : Generate from the data file a configuration which is vendor-specific
• Example of data file : Yaml

  • hostname R1
    vlans:
      - id: 2
      name: Python
      - id: 3
      name: Java

Data collection

• Usually done with SNMP
  • Limited to the available MIBS
• With an API
  • Limited by the API and the code that process the data

Migrations

• If the configuration files are vendor independant
  • Migration of a network infrastructure to another vendor is straighforward.
  • Migration can be done gradually.
  • Tests of your configuration can be done before going in production.
• But before starting to build automation in your network
  • Document, Document and Document again.
  • The steps to maintain the network must be clear enough to be understood without relying on proprietary interfaces.
    • Very similar to a high level software specification

Compliance

• Similar to code quality compliance
  • Example :
    • Hostname should start with an uppercase.
    • Remote vty should only be accessible by ssh.

Reporting

• Once you can get the configuration of the device which is structured and accessible from an API
• The data can be represented in the way you want.
  • Example :
    • a list of network interfaces and their neighbords can be displayed as a graph of nodes.
    • Vlans configured in the network can be reported.
    • Available/Seen hosts in the network according to the ARP cache table.

Troubleshooting

• First you must think about the way you troubleshoot before automating it.
  • ping, traceroute, local IP routes.

Configuration Management

• Generated configurations can be stored and versionned in a repository
  • They can be reviewed before testing them.
  • They can be automatically tested before pushing them in production.
    • gitlab for networks config