Скачать или смотреть Data Models And Supporting Protocols (YANG NETCONF & RESTCONF| 8.9 Network automation

The IETF's Network Cofiguration Protocol and Yang data modeling language promise to help simplify and speed network device configuration

This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note it will likely favor the submitter’s approach.

Service provider and enterprise network teams that are moving towards a service-oriented approach to network management are reaching for the IETF’s Network Configuration Protocol (NETCONF) and YANG, a data modeling language, to help remove the time, cost, and manual steps involved in network element configuration.

NETCONF is the standard for installing, manipulating, and deleting configuration of network devices while YANG is used to model both configuration and state data of network elements. YANG structures the data definitions into tree structures and provides many modeling features, including an extensible type system, formal separation of state and configuration data, and a variety of syntactic and semantic constraints. YANG data definitions are contained in modules and provide a strong set of features for extensibility and reuse.

What does this mean? Network automation is currently blocked by current approaches where you need to write device-specific CLI scripts or are locked into rigid closed tools. There is nothing wrong with CLIs; they are perfect for humans, but less optimal for software. NETCONF is defined for the transaction-safe configuration of devices. This means that scenarios like setting up the initial configuration for a range of devices, changing ACLs, and adding VPNs, can be performed automatically while keeping flexibility and vendor independence.

Additionally, time-to-market requirements in delivering new services are critical and any delay in configuring the corresponding devices directly affects deployment and can have a big impact on revenue. Organizations are seeing the need to get the people out of the way to automate the configuration and implementation of network devices.

Ultimately the technology is designed to support more robust management of configuration, including configuration change transactions including rollbacks, the strong separation between configuration and state data allowing for efficient backup-and-restore, selective data retrieval with filtering using well-known query mechanisms, and streaming and playback of event notifications.

The current scale of networking across service providers, enterprises, and cloud providers poses unprecedented challenges to operations teams. As both frequency and complexity of changes made to the network, as well as the cost of failed configurations, explode, network operations teams understand the cost savings that come with delivering services quickly and are now requiring the use of NETCONF and YANG in their environments to achieve these benefits. Compound this with all the other challenges organizations face -- including frequent network changes, service agility, network complexity, SLAs becoming tighter and simply doing more with less -- it is no wonder networking teams are losing sleep.

YANG is a data modeling language for the NETCONF configuration management protocol. Together, NETCONF and YANG provide the tools that network administrators need to automate configuration tasks across heterogeneous devices in a software-defined network (SDN).