Chapter 12
Model-Driven Programmability
This chapter covers the following topics:
NETCONF: This section introduces NETCONF—what it is, why it has
been developed, and how to use it.
YANG: This section covers YANG, YANG data models, and how these
data models apply to networking.
RESTCONF: This section covers RESTCONF, how it compares to
NETCONF, and how to use it.
Model-Driven Telemetry: This section provides a brief introduction
to model-driven telemetry.
This chapter introduces the concepts of model-driven
programmability. It discusses what led to the
implementation of data models in networking and the
advantages data models bring to network
configuration and monitoring. This chapter begins by
introducing the network programmability interfaces
that network operating systems from Cisco are
exposing. It then takes an in-depth look at NETCONF,
why was it necessary to come up with yet another
network configuration protocol, and the drawbacks
and limitations that it addresses compared to similar
protocols. It is difficult to talk about NETCONF
without also talking about YANG, and this chapter
therefore covers network data modeling. The chapter
also includes sections on RESTCONF and model-
driven telemetry. You will find peppered throughout
this chapter examples of YANG data models and tools
and libraries to interact with these models (for
example, pyang and ncclient). This chapter gives
special focus to Cisco IOS XE and Cisco NX-OS and
their implementations of model-driven