NETCONF YANG Network Automation: Practical Guide

NETCONF and YANG: Automating Networks with Data Models

April 15, 2026·2 min read·295 words

NETCONF (RFC 6241) + YANG (RFC 7950) are the modern standards for programmatic multi-vendor configuration. NETCONF is a protocol (XML/SSH), while YANG is a data modeling language. They are natively supported by Cisco IOS-XE/NX-OS, Juniper Junos, Arista EOS, and Nokia. They are gradually replacing CLI parsing.

Why NETCONF/YANG

CLI parsing is fragile (syntax changes break scripts)
NETCONF uses structured XML for reliable parsing
YANG provides schemas for validation before deployment
Atomic transactions (commit/rollback)
Multi-vendor standard

NETCONF

Transport: SSH port 830 or TLS 6513
Payload: structured XML
Operations: get, get-config, edit-config, copy-config, delete-config, lock, unlock, close, kill, commit
Candidate/running/startup datastores
Capability advertisement

YANG

Modeling language (similar to JSON Schema)
Hierarchical structure: containers, lists, leaves
Types: string, int, boolean, enum
Standards: OpenConfig (multi-vendor), IETF, vendor-specific (Cisco-YANG, Junos-YANG)
Version: YANG 1.1 (RFC 7950)

OpenConfig: multi-vendor standard

Consortium: Google, Microsoft, Apple, and network operators
Cross-vendor models: interfaces, BGP, routing, LLDP
Used by Cisco, Arista, Juniper, and Nokia
Vision: write-once, run-anywhere automation

NETCONF + Python (ncclient) example

from ncclient import manager
with manager.connect(host='10.0.0.1', port=830, username='admin', password='pass', hostkey_verify=False) as m:
config = m.get_config(source='running').data_xml
print(config)

gNMI

gRPC Network Management Interface: a modern gRPC-based alternative
Higher performance than NETCONF/XML
Native streaming telemetry
Supported by Cisco IOS-XE 16.10+, Arista, and Nokia
Growing adoption in 2026

Streaming telemetry

Push model: the device sends metrics regularly
Replaces SNMP polling
Transport: gNMI, gRPC, Kafka
Collectors: Prometheus, InfluxDB, Grafana

Tools

ncclient (Python): NETCONF library
pyang: YANG model validation
pyangbind: YANG → Python objects
gnmic: gNMI CLI client
gnxi: gNMI + gNOI from Google

Adoption in France in 2026

ISPs/network operators: mature NETCONF + OpenConfig adoption
Large enterprises: migration underway
SMEs and mid-sized companies: still using CLI + Netmiko/Ansible
Evolution: slow but inevitable

Order from OPTINOC

NETCONF/YANG + gNMI training. Streaming telemetry deployment. OpenConfig integration. Quote within 48 hours.

Frequently Asked Questions

Quelle est la différence entre NETCONF et RESTCONF ?

NETCONF utilise SSH (port 830) avec des messages XML et supporte les transactions, le verrouillage de datastore et les notifications. RESTCONF utilise HTTPS avec JSON ou XML, est plus simple mais moins complet. NETCONF est préféré pour les opérations transactionnelles critiques.

Tous les équipements réseau supportent-ils NETCONF ?

Non, mais la majorité des équipements modernes le supportent : Cisco IOS-XE, IOS-XR, NX-OS, Juniper Junos, Arista EOS, Nokia SR OS. Les anciens équipements IOS classiques ne le supportent généralement pas.

Comment trouver les modèles YANG d'un équipement ?

Utilisez la commande NETCONF get-schema ou explorez le dépôt GitHub github.com/YangModels/yang. Sur Cisco IOS-XE, la commande show platform software yang-management process state liste les modèles disponibles.