fabric-orchestrator/src/yang

YANG Module

This module provides YANG path constants and utilities for managing Arista EVPN-VXLAN fabrics via gNMI.

Overview

The module contains validated gNMI paths for Arista EOS 4.35.0F, organized by feature:

Class	Model	Description
Interfaces	OpenConfig	Physical and logical interfaces
Loopbacks	OpenConfig	Loopback interfaces
VLANs	OpenConfig	VLAN configuration and SVIs
BGP	OpenConfig	BGP global, neighbors, AFI-SAFI
VXLAN	Arista Exp	VXLAN VNI mappings
MLAG	Arista Exp	MLAG config (state via eAPI)
EVPN	Arista Exp	EVPN instances (state via eAPI)
PortChannel	OpenConfig	LAG/Port-Channel
System	OpenConfig	System configuration

Installation

from yang.paths import Interfaces, BGP, VXLAN

Usage Examples

Interfaces

from yang.paths import Interfaces

# Get all interfaces
path = Interfaces.ROOT
# -> "/interfaces/interface"

# Get specific interface
path = Interfaces.interface("Ethernet1")
# -> "/interfaces/interface[name=Ethernet1]"

# Get interface state
path = Interfaces.state("Ethernet1")
# -> "/interfaces/interface[name=Ethernet1]/state"

# Get operational status
path = Interfaces.oper_status("Ethernet1")
# -> "/interfaces/interface[name=Ethernet1]/state/oper-status"

Loopbacks

from yang.paths import Loopbacks

# Get loopback interface
path = Loopbacks.interface(0)
# -> "/interfaces/interface[name=Loopback0]"

# Use predefined constants
path = Loopbacks.LOOPBACK0  # Router ID
path = Loopbacks.LOOPBACK1  # VTEP source

VLANs

from yang.paths import VLANs

# Get all VLANs
path = VLANs.ROOT
# -> "/network-instances/network-instance[name=default]/vlans/vlan"

# Get specific VLAN
path = VLANs.vlan(40)
# -> "/network-instances/network-instance[name=default]/vlans/vlan[vlan-id=40]"

# Get SVI interface
path = VLANs.svi(40)
# -> "/interfaces/interface[name=Vlan40]"

BGP

from yang.paths import BGP, AfiSafi

# Get all neighbors
path = BGP.NEIGHBORS
# -> "/network-instances/.../bgp/neighbors/neighbor"

# Get specific neighbor
path = BGP.neighbor("10.0.1.0")

# Get neighbor session state
path = BGP.neighbor_session_state("10.0.1.0")

# Get EVPN AFI-SAFI for neighbor
path = BGP.neighbor_afi_safi("10.0.250.1", AfiSafi.L2VPN_EVPN)

VXLAN

from yang.paths import VXLAN

# Get all VNI mappings
path = VXLAN.VLAN_TO_VNIS
# -> "/interfaces/interface[name=Vxlan1]/arista-vxlan/vlan-to-vnis"

# Get specific VNI
path = VXLAN.vlan_to_vni(40)
# -> ".../vlan-to-vnis/vlan-to-vni[vlan=40]"

# Get L3 VNI (VRF-to-VNI)
path = VXLAN.vrf_to_vni("gold")
# -> ".../vrf-to-vnis/vrf-to-vni[vrf=gold]"

# Get VTEP source interface config
path = VXLAN.SOURCE_INTERFACE

MLAG

from yang.paths import MLAG

# Get MLAG config
path = MLAG.CONFIG
# -> "/arista/eos/mlag/config"

# ⚠️ Note: MLAG state is NOT available via gNMI
# Use eAPI for: show mlag

EVPN

from yang.paths import EVPN

# Get all EVPN instances
path = EVPN.INSTANCES
# -> "/arista/eos/evpn/evpn-instances"

# Get specific instance
path = EVPN.instance("40")

# Get route-targets
path = EVPN.route_target("40")

# ⚠️ Note: EVPN state is NOT available via gNMI
# Use eAPI for: show bgp evpn

Port-Channel

from yang.paths import PortChannel

# Get port-channel interface
path = PortChannel.interface(999)
# -> "/interfaces/interface[name=Port-Channel999]"

# Get LAG aggregation config
path = PortChannel.aggregation(999)

Subscriptions

from yang.paths import FabricSubscriptions, SubscriptionPath

# Get pre-built subscription paths
for sub in FabricSubscriptions.all():
    print(f"Path: {sub.path}, Mode: {sub.mode}")

# Individual subscriptions
sub = FabricSubscriptions.INTERFACE_STATE
sub = FabricSubscriptions.BGP_SESSIONS
sub = FabricSubscriptions.VXLAN_VNIS

# Create custom subscription
custom = SubscriptionPath(
    path="/interfaces/interface[name=Ethernet1]/state",
    mode="on-change"
)

Limitations

Feature	Config	State	Notes
MLAG	✅	❌	Use eAPI for state
EVPN	✅	❌	Use eAPI for state

References

• Full YANG Paths Documentation
• Arista YANG Models
• OpenConfig Models