Programmability and Your Network with Cisco IOS XR · No or minimal programming experience Requires • Simple programming abstractions • Avoid programming complexities of management

Santiago Álvarez

Akshat SharmaJan 2018

Programmability and Your Network with Cisco IOS XR

@111pontes

@irakshat

@xrdocs

© 2017 Cisco and/or its affiliates. All rights reserved. Cisco Confidential

• Speed and scale demand software automation and data analytics

• Rapid innovation as competitive advantage

• One network operator per 1000s / 10000s of complex network devices.

Motivations for Network Programmability


Cisco IOS XR Device Programmability

Data Plane

Control Plane

Management Plane

App

Controller

Orchestrator

Controller

Orchestrator

Data Plane

Control Plane

App

Model-Driven Manageability Service Layer API


Model-Driven Manageability

Encoding XML JSON GPB

Protocol NETCONF gRPCRESTCONF

Models

APIs

Apps

Model-Driven APIs

YANG Development Kit (YDK)

YANG Models

(native, open)

App App App

SSH HTTPTransport

Model-Driven Configuration

Model-Driven Telemetry


Benefits of Model-Driven Manageability

• Model based, structured, computer friendly

• Multiple model types (native, OpenConfig, IETF, etc.)

• Models decoupled from transport, protocol and encoding

• Choice of transport, protocol and encoding

• Model-driven APIs for abstraction and simplification

• Wide standard support while leveraging open source


• Data (config and operational) and actions (RPCs) in a tree structure

• Self-documented and shipped with devices

• Native models provide most coverage

• OpenConfig and IETF models are mapped to native models

Data Models In Cisco IOS XR

Cisco IOS XRNative

Open(OpenConfig / IETF)


• Provide most comprehensive coverage for device functionality

• Approximately ~375 models in XR 6.3.1 (750+ YANG files)

• A single model defines either configuration (cfg), operational state (oper) or an action (act)

• Cisco-IOS-XR-ipv4-bgp-cfg

• Cisco-IOS-XR-ipv4-bgp-oper

• Cisco-IOS-XR-ipv4-bgp-act

• Models posted at

• https://github.com/YangModels/yang/tree/master/vendor/cisco/xr

Cisco IOS XR Native Data Models

https://github.com/YangModels/yang/tree/master/vendor/cisco/xr


• OpenConfig models mapped to native models

• Comprehensive support in Cisco IOS XR (as of 6.3.1)

• bgp, bgp-policy

• Interfaces, if-aggregate, if-ethernet, if-ip

• lacp

• local-routing

• mpls

• platform

• rib-bgp

• routing-policy

• telemetry

• vlan

• channel_monitor, terminal_device, optical_amplifier, transport_line_common, transport_line_protection, transport_types

OpenConfig Data Models In Cisco IOS XR

Cisco IOS XRNative


Network Engineer

Skills

• Proficient in network protocols and network management

• No or minimal programming experience

Requires

• Simple programming abstractions

• Avoid programming complexities of management protocols, encodings, transport and YANG

Software Developer

Skills

• Proficient in software development and automation

• No or minimal experience with network protocols and network management

Requires

• Software development kit

• Avoid learning curb of management protocols, encodings, transport and YANG

Two User Profiles for Network Programmability


• Simplify app development

• One-to-one correspondence between model and class hierarchy

• Abstract protocol, transport, encoding, modeling language

• API generated from YANG model

• Rich data validation

• Multi-language (Python, C++, Go, etc.)

Model-Driven APIs

YANG ModelClass Hierarchy

(Python, C++, Go)


• Simplicity through abstractions (model bundles, services, providers)

• Rich data validation (type, value, semantics, config/oper)

• Multilanguage support (Python, C++)

• New infrastructure introduced release 0.6.0

• Improved data validation (dynamic model download)

• More providers (RESTCONF, OpenDaylight)

• Low-level Path API (no model bundles required)

• Improved data filtering (config/oper)

• Rapid development

• Initial release 0.3.0 - March 2016

• Latest release 0.6.3 - December 2017

YANG Development Kit (ydk.io)

CRUD / NETCONF / Executor

NETCONF / RESTCONF / OpenDaylight

Cisco IOS XR

OpenConfig IETFCisco IOS XEModel

Bundles

Services

Providers

Cisco IOS XR

http://ydk.io/


A YDK-Py “Hello World” Using OpenConfig BGP

# Cisco YDK-Py OC-BGP “Hello world”from ydk.services import CRUDServicefrom ydk.providers import NetconfServiceProviderfrom ydk.models.openconfig import openconfig_bgp as oc_bgp

if __name__ == "__main__":provider = NetconfServiceProvider(address="10.0.0.1",

port=830,username=“admin”,password=“admin”,protocol=“ssh”)

crud = CRUDService() # create CRUD servicebgp = oc_bgp.Bgp() # create oc-bgp objectbgp.global_.config.as_ = 65000 # set local AS numbercrud.create(provider, bgp) # create on NETCONF deviceprovider.close()exit()

# End of script

module: openconfig-bgp+--rw bgp

+--rw global| +--rw config| | +--rw as| | +--rw router-id?| +--ro state| | +--ro as| | +--ro router-id?| | +--ro total-paths?| | +--ro total-prefixes?

...


• Automated push of model data

• Facilitates close-loop automation

• Numerous use cases

• Network health

• Troubleshooting / remediation

• Performance tuning

• Capacity planning

• Security

• Cadence and event-based

• Collector dial-in or router dial-out

• Highly efficient processing and encoding

Model-Driven Telemetry

Configuration Telemetry

Controller(Network Analytics)



Data Plane

Control Plane

Management Plane

App

Controller

Orchestrator

Controller

Orchestrator

Data Plane

Control Plane

App


• Batch updates straight to RIB, LSD (and more in the future), without going through Network state database.

• Streaming Notifications (e.g. BFD events, Interface events…)

Performance API for the “Do-it-yourself"system

• Bring your own Protocol –Use the same APIs that Network OS protocol stacks use internally, but over GRPC/thrift.

• Users can focus on higher layer protocols and Controller logic.

• Leverage Network OS infrastructure layer for Lower Level Functionality that includes scalability and data plane abstraction.

Offload Low-level tasks to Network OS

The case for Service Layer APIs

Model Driven Remote Procedure call (RPC) support

Enables consistency in Application Development.

gRPC, thrift are powerful RPC examples suitable for the performance requirements at this layer.

A clean separation of concerns between the infrastructure layer and management/Protocol layer.

It is crucial to have a singular focus for this layer – enabling Cisco to focus on just the right amount of software, with a complete API.

A Layered approach to APIs

Building Service Layer APIs for Today’s Use Cases

Models act as versioned Contracts – easier to understand, document and version.

Protobuf IDLs, or YANG are examples of IDLs that may be used to model this API layer.

Controllers

Service Layer API Architecture

SL-API Functionality Domains

InitializationRPCs

RIB RPCs

MPLS RPCs

InterfaceRPCs

BFDRPCs

gRPC Server (Router)

Protobuf Schema/Model

……

gRPC stub

gRPC stub

On-Box Client

Off-Box

ClientRequest

Response

Python, C++, go

Python, C++, go

“The Use Cases are Evolving ...”

Programmable Route Downloads

Controller/Agent

Programmable route downloads to CDN PoP routers to optimize TCAM space.

IOS-XR

IOS-XR

Traffic Engineering and Path Selection:

IOS-XR

IOS-XR

Controllers

Engineering paths for applications through Route/label manipulation, all based on user specific logic.

IOS-XR

IOS-XR

IOS-XR

IOS-XR

IOS-XR

IOS-XR

IOS-XR

Bring your own Protocol/Agent

On-box agents and custom protocols (e.g. openR) that co-exist with Cisco protocols to influence routing.

IOS-XR

IOS-XR

IOS-XR

IOS-XR

IOS-XR

IOS-XR

IOS-XRIOS-XR

IOS-XR

IOS-XR



Data Plane

Control Plane

Management Plane

App

Controller

Orchestrator

Controller

Orchestrator

Data Plane

Control Plane

App



Resources


• YDK Portal - http://ydk.io

• Service Layer Documentation @xrdocs -https://xrdocs.github.io/cisco-service-layer

Resources

http://ydk.io/

https://xrdocs.github.io/cisco-service-layer


How to Get YDK-Py

Native Virtual Cloud

Install PythonInstall YDKDownload ydk-py-samples

Install VagrantInstall VirtualboxDownload ydk-py-samples

YANG Development Kit Sandbox

https://github.com/CiscoDevNet/ydk-py-samples



YDK Portal

• YDK at DevNet (http://ydk.io)

YDK Sample Apps

• YDK-Py sample apps (https://github.com/CiscoDevNet/ydk-py-samples) - Over 700 apps!

• YDK-Cpp sample apps (https://github.com/CiscoDevNet/ydk-cpp-samples ) - Coming soon

Sandboxes

• dCloud YANG Development Kit sandbox (https://goo.gl/RPpBvL)

• Ubuntu YDK Vagrant box (https://git.io/vaw1U)

Support

• Cisco support community (https://communities.cisco.com/community/developer/ydk)

Detailed YDK Resources

http://ydk.io/


https://github.com/CiscoDevNet/ydk-cpp-samples

https://goo.gl/RPpBvL

https://git.io/vaw1U

https://communities.cisco.com/community/developer/ydk


YDK Documentation

• YDK-Py docs (http://ydk.cisco.com/py/docs)

• YDK-Cpp docs (http://ydk.cisco.com/cpp/docs)

GitHub

• YDK Python API – YDK-Py (https://git.io/vaWsg)

• YDK-Py sample apps (https://git.io/vaw1U)

• YDK C++ API – YDK-Cpp (https://git.io/v1Cst) - alpha

• YDK-Cpp sample apps (https://git.io/v14Qh) - coming soon

Detailed YDK Resources (cont.)

http://ydk.cisco.com/py/docs

http://ydk.cisco.com/cpp/docs

https://git.io/vaWsg

https://git.io/vaw1U

https://git.io/v1Cst

https://git.io/v14Qh


Conferences

• NANOG 68: Ok, We Got YANG Data Models. Now What? (http://youtu.be/2oqkiZ83vAA )

• NANOG 71: Getting started with OpenConfig (https://youtu.be/L7trUNK8NJI)

• LinuxCon NA 2016: Simplifying Network Programmability Using Model-Driven APIs (https://goo.gl/W6tH2X)

Detailed YDK Resources (cont.)

http://youtu.be/2oqkiZ83vAA

https://youtu.be/L7trUNK8NJI

https://goo.gl/W6tH2X

Cisco IOS-XR Service Layer APIs

• Github: Check out the Obj-model repository on Github at

https://github.com/Cisco-Service-Layer/service-layer-objmodel

Proto definitions of the latest RPC versions Exhaustive python Unit Tests and tutorials to get

started

• @xrdocs: Blogs, Tutorials on Using Service Layer APIs and associated Libraries:

https://xrdocs.github.io/cisco-service-layer/

• APIdocs: Doxygen based documentation, auto-generated from the proto files:

https://xrdocs.github.io/cisco-service-layer/apidocs/

Github

APIdocs @xrdocs


https://xrdocs.github.io/cisco-service-layer/




Documents

Programmability and Your Network with Cisco IOS XR · No or minimal programming experience Requires • Simple programming abstractions • Avoid programming complexities of management