# NetBox Data Model for Fabric Orchestrator

This document describes how fabric intent is represented in NetBox for the fabric-orchestrator to consume.

## Overview

The fabric-orchestrator uses NetBox as the **source of truth** for EVPN-VXLAN fabric configuration. Instead of using ConfigContexts, we leverage NetBox's native data models plus the [NetBox BGP Plugin](https://github.com/netbox-community/netbox-bgp) for comprehensive fabric representation.

### Requirements

- NetBox 4.4.x
- NetBox BGP Plugin v0.17.x

---

## Data Model Summary

### Native NetBox Models

| Feature | NetBox Model | API Endpoint |
|---------|--------------|--------------|
| **Devices** | `dcim.Device` | `/api/dcim/devices/` |
| **Interfaces** | `dcim.Interface` | `/api/dcim/interfaces/` |
| **LAGs/Port-Channels** | `dcim.Interface` (type=LAG) | `/api/dcim/interfaces/` |
| **VLANs** | `ipam.VLAN` | `/api/ipam/vlans/` |
| **VLAN Groups** | `ipam.VLANGroup` | `/api/ipam/vlan-groups/` |
| **VRFs** | `ipam.VRF` | `/api/ipam/vrfs/` |
| **Route Targets** | `ipam.RouteTarget` | `/api/ipam/route-targets/` |
| **IP Addresses** | `ipam.IPAddress` | `/api/ipam/ip-addresses/` |
| **Prefixes** | `ipam.Prefix` | `/api/ipam/prefixes/` |
| **ASNs** | `ipam.ASN` | `/api/ipam/asns/` |
| **L2VPN (EVPN)** | `vpn.L2VPN` | `/api/vpn/l2vpns/` |
| **L2VPN Terminations** | `vpn.L2VPNTermination` | `/api/vpn/l2vpn-terminations/` |

### NetBox BGP Plugin Models

| Feature | Plugin Model | API Endpoint |
|---------|--------------|--------------|
| **BGP Sessions** | `netbox_bgp.BGPSession` | `/api/plugins/bgp/sessions/` |
| **BGP Peer Groups** | `netbox_bgp.PeerGroup` | `/api/plugins/bgp/peer-groups/` |
| **BGP Communities** | `netbox_bgp.Community` | `/api/plugins/bgp/communities/` |
| **Routing Policies** | `netbox_bgp.RoutingPolicy` | `/api/plugins/bgp/routing-policies/` |
| **Prefix Lists** | `netbox_bgp.PrefixList` | `/api/plugins/bgp/prefix-lists/` |
| **AS Path Lists** | `netbox_bgp.ASPathList` | `/api/plugins/bgp/as-path-lists/` |

---

## Custom Fields Reference

NetBox doesn't natively support all fabric-specific configurations. The following custom fields must be created to support MLAG, ASN assignment, and VRF extensions.

### Complete Custom Fields List

#### Device Custom Fields

| Field Name | Label | Type | Required | Description |
|------------|-------|------|----------|-------------|
| `asn` | ASN | Integer | No | BGP Autonomous System Number assigned to this device |
| `mlag_domain_id` | MLAG Domain ID | Text | No | MLAG domain identifier (e.g., "leafs") |
| `mlag_peer_address` | MLAG Peer Address | Text | No | MLAG peer IP address |
| `mlag_local_address` | MLAG Local Address | Text | No | MLAG local IP address |
| `mlag_virtual_mac` | MLAG Virtual MAC | Text | No | Shared virtual-router MAC (e.g., "c001.cafe.babe") |

#### Interface Custom Fields

| Field Name | Label | Type | Required | Description |
|------------|-------|------|----------|-------------|
| `mlag_peer_link` | MLAG Peer Link | Boolean | No | Marks interface as MLAG peer-link |
| `mlag_id` | MLAG ID | Integer | No | MLAG port-channel ID for host-facing LAGs |

#### VRF Custom Fields

| Field Name | Label | Type | Required | Description |
|------------|-------|------|----------|-------------|
| `l3vni` | L3 VNI | Integer | No | Layer 3 VNI for EVPN symmetric IRB |
| `vrf_vlan` | VRF VLAN | Integer | No | VLAN ID used for L3 VNI SVI |

#### IP Address Custom Fields

| Field Name | Label | Type | Required | Description |
|------------|-------|------|----------|-------------|
| `virtual_ip` | Virtual IP | Boolean | No | Marks IP as anycast/virtual IP (shared across MLAG pair) |

### Custom Field Creation via API

```bash
# Example: Create ASN custom field on Device
curl -X POST "https://netbox.example.com/api/extras/custom-fields/" \
  -H "Authorization: Token $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "content_types": ["dcim.device"],
    "name": "asn",
    "label": "ASN",
    "type": "integer",
    "required": false,
    "description": "BGP Autonomous System Number assigned to this device"
  }'

# Example: Create MLAG Peer Link custom field on Interface
curl -X POST "https://netbox.example.com/api/extras/custom-fields/" \
  -H "Authorization: Token $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "content_types": ["dcim.interface"],
    "name": "mlag_peer_link",
    "label": "MLAG Peer Link",
    "type": "boolean",
    "required": false,
    "description": "Marks interface as MLAG peer-link"
  }'
```

---

## Fabric Component Mapping

### Devices and Roles

| Fabric Role | NetBox Device Role | Description |
|-------------|-------------------|-------------|
| Spine | `spine` | Spine switches (AS 65000) |
| Leaf | `leaf` | Leaf switches (AS 65001-65004) |

**Example Device Setup:**
- `spine1`, `spine2` - Device Role: spine
- `leaf1` through `leaf8` - Device Role: leaf

### Interfaces

| Interface Type | NetBox Interface Type | Usage |
|----------------|----------------------|-------|
| Physical uplinks | `1000base-t` / `10gbase-x-sfpp` | Spine-Leaf connections |
| Loopback0 | `virtual` | BGP Router-ID |
| Loopback1 | `virtual` | VTEP source (shared by MLAG pair) |
| Port-Channel | `lag` | MLAG peer-link, host bonds |
| Vxlan1 | `virtual` | VXLAN tunnel interface |
| SVI | `virtual` | VLAN interfaces (Vlan40, etc.) |

### IP Addressing Scheme

Based on the reference topology:

| Purpose | Prefix | Example |
|---------|--------|---------|
| Spine-Leaf P2P (Spine1) | `10.0.1.0/24` | `10.0.1.0/31`, `10.0.1.2/31`, ... |
| Spine-Leaf P2P (Spine2) | `10.0.2.0/24` | `10.0.2.0/31`, `10.0.2.2/31`, ... |
| MLAG iBGP Peer | `10.0.3.0/24` | `10.0.3.0/31` per MLAG pair |
| MLAG Peer VLAN 4090 | `10.0.199.0/24` | `/31` per MLAG pair |
| Loopback0 (Router-ID) | `10.0.250.0/24` | Spine: `.1-.2`, Leaf: `.11-.18` |
| Loopback1 (VTEP) | `10.0.255.0/24` | `.11-.14` (shared per MLAG pair) |

---

## BGP Configuration

### ASN Assignments

| Device(s) | ASN | Type | Custom Field |
|-----------|-----|------|--------------|
| spine1, spine2 | 65000 | eBGP | `asn: 65000` |
| leaf1, leaf2 | 65001 | iBGP pair | `asn: 65001` |
| leaf3, leaf4 | 65002 | iBGP pair | `asn: 65002` |
| leaf5, leaf6 | 65003 | iBGP pair | `asn: 65003` |
| leaf7, leaf8 | 65004 | iBGP pair | `asn: 65004` |

### BGP Sessions (Plugin)

#### Underlay eBGP Sessions

Each leaf has eBGP sessions to both spines over point-to-point interfaces:

| Local Device | Local IP | Remote Device | Remote IP | Remote ASN |
|--------------|----------|---------------|-----------|------------|
| leaf1 | 10.0.1.1 | spine1 | 10.0.1.0 | 65000 |
| leaf1 | 10.0.2.1 | spine2 | 10.0.2.0 | 65000 |

#### Underlay iBGP Sessions

Each MLAG pair has an iBGP session for redundancy:

| Local Device | Local IP | Remote Device | Remote IP | Notes |
|--------------|----------|---------------|-----------|-------|
| leaf1 | 10.0.3.0 | leaf2 | 10.0.3.1 | next-hop-self |

#### Overlay EVPN Sessions

EVPN sessions use loopback addresses with `ebgp-multihop 3`:

| Local Device | Local IP (Lo0) | Remote Device | Remote IP (Lo0) | AFI/SAFI |
|--------------|----------------|---------------|-----------------|----------|
| leaf1 | 10.0.250.11 | spine1 | 10.0.250.1 | L2VPN EVPN |
| leaf1 | 10.0.250.11 | spine2 | 10.0.250.2 | L2VPN EVPN |

### BGP Peer Groups (Plugin)

| Peer Group | Purpose | Key Settings |
|------------|---------|--------------|
| `underlay` | eBGP to spines | `remote-as 65000`, `maximum-routes 12000` |
| `underlay_ibgp` | iBGP to MLAG peer | `next-hop-self` |
| `evpn` | EVPN overlay | `update-source Loopback0`, `ebgp-multihop 3`, `send-community extended` |

---

## VXLAN / EVPN Configuration

### L2VPN for EVPN VNI Mappings

NetBox's L2VPN model represents EVPN instances:

| L2VPN Name | Type | Identifier (VNI) | Description |
|------------|------|------------------|-------------|
| `VLAN40-L2VNI` | EVPN | 100040 | L2 VXLAN for VLAN 40 |
| `VRF-gold` | EVPN | 100001 | L3 VNI for VRF gold |

### L2VPN Terminations

Link VLANs to L2VPNs on specific devices:

| L2VPN | Device | Interface/VLAN |
|-------|--------|----------------|
| `VLAN40-L2VNI` | leaf1 | VLAN 40 |
| `VLAN40-L2VNI` | leaf2 | VLAN 40 |
| `VLAN40-L2VNI` | leaf5 | VLAN 40 |
| `VLAN40-L2VNI` | leaf6 | VLAN 40 |

### Route Targets

| VRF/VLAN | Import RT | Export RT |
|----------|-----------|-----------|
| VLAN 40 | `40:100040` | `40:100040` |
| VRF gold | `1:100001` | `1:100001` |

---

## MLAG Configuration

MLAG configuration uses Custom Fields since NetBox doesn't have native MLAG support.

### MLAG Pair Configuration

| Device | Domain ID | Local IP | Peer IP | Virtual MAC |
|--------|-----------|----------|---------|-------------|
| leaf1 | leafs | 10.0.199.254 | 10.0.199.255 | c001.cafe.babe |
| leaf2 | leafs | 10.0.199.255 | 10.0.199.254 | c001.cafe.babe |

### MLAG-Related VLANs

| VLAN | Name | Purpose | Trunk Group |
|------|------|---------|-------------|
| 4090 | mlag-peer | MLAG peer communication | mlag-peer |
| 4091 | mlag-ibgp | iBGP between MLAG peers | mlag-peer |

---

## VRF Configuration

### VRF Definition

| VRF Name | RD | Import RT | Export RT | L3 VNI (custom field) |
|----------|-------|-----------|-----------|----------------------|
| gold | `10.0.250.X:1` | `1:100001` | `1:100001` | 100001 |

> Note: RD uses device's Loopback0 IP for uniqueness

### VRF Interface Assignment

SVIs are assigned to VRFs in NetBox. VRF membership is tracked via IP addresses assigned to interfaces:

| Interface | VRF | IP Address | Virtual IP (custom field) |
|-----------|-----|------------|---------------------------|
| Vlan34 (leaf3) | gold | 10.34.34.2/24 | No |
| Vlan34 (leaf4) | gold | 10.34.34.3/24 | No |
| Vlan34 (leaf3) | gold | 10.34.34.1/24 | Yes (anycast) |
| Vlan78 (leaf7) | gold | 10.78.78.2/24 | No |
| Vlan78 (leaf8) | gold | 10.78.78.3/24 | No |
| Vlan78 (leaf7) | gold | 10.78.78.1/24 | Yes (anycast) |

---

## Data Retrieval Strategy

The fabric-orchestrator retrieves intent from NetBox using pynetbox:

```python
import pynetbox

nb = pynetbox.api('http://netbox.example.com', token='your-token')

# Get all leaf devices
leaves = nb.dcim.devices.filter(role='leaf')

# Get device ASN from custom field
device = nb.dcim.devices.get(name='leaf1')
asn = device.custom_fields.get('asn')

# Get BGP sessions for a device
bgp_sessions = nb.plugins.bgp.sessions.filter(device='leaf1')

# Get L2VPNs (EVPN)
l2vpns = nb.vpn.l2vpns.filter(type='evpn')

# Get VLAN-to-VNI mappings via L2VPN terminations
terminations = nb.vpn.l2vpn_terminations.filter(l2vpn='VLAN40-L2VNI')

# Get VRF with L3 VNI
vrf = nb.ipam.vrfs.get(name='gold')
l3vni = vrf.custom_fields.get('l3vni')
```

---

## Relationship Diagram

```
┌─────────────────────────────────────────────────────────────────────────────┐
│                              NetBox                                         │
├─────────────────────────────────────────────────────────────────────────────┤
│                                                                             │
│  ┌────────────┐     ┌────────────────┐     ┌───────────────┐               │
│  │  Device    │─────│  Interface     │─────│ IP Address    │               │
│  │ (leaf1)    │     │ (Loopback0)    │     │(10.0.250.11)  │               │
│  │ cf:asn     │     │ cf:mlag_peer_  │     │ cf:virtual_ip │               │
│  └────────────┘     │    link        │     └───────────────┘               │
│        │            └────────────────┘                                      │
│        │                                                                    │
│        │ custom_fields                                                      │
│        ▼                                                                    │
│  ┌────────────┐                                                             │
│  │  cf:asn    │                                                             │
│  │ (65001)    │                                                             │
│  └────────────┘                                                             │
│                                                                             │
│  ┌──────────────────┐     ┌───────────────────┐                             │
│  │ BGP Session      │─────│   Peer Group      │                             │
│  │ (plugin)         │     │   (plugin)        │                             │
│  └──────────────────┘     └───────────────────┘                             │
│                                                                             │
│  ┌────────────┐     ┌───────────────────────┐     ┌────────────┐           │
│  │   VLAN     │─────│ L2VPN Termination     │─────│  L2VPN     │           │
│  │  (40)      │     │                       │     │ (EVPN)     │           │
│  └────────────┘     └───────────────────────┘     └────────────┘           │
│                                                          │                  │
│                                                          │ identifier       │
│                                                          ▼                  │
│                                                   ┌────────────┐            │
│                                                   │  100040    │            │
│                                                   │  (VNI)     │            │
│                                                   └────────────┘            │
│                                                                             │
│  ┌────────────┐     ┌───────────────────┐                                   │
│  │   VRF      │─────│  Route Target     │                                   │
│  │ (gold)     │     │ (1:100001)        │                                   │
│  │ cf:l3vni   │     └───────────────────┘                                   │
│  └────────────┘                                                             │
│                                                                             │
└─────────────────────────────────────────────────────────────────────────────┘
```

---

## API Filter Compatibility Notes

### Working Filters (NetBox 4.4)

| Endpoint | Filter | Example |
|----------|--------|---------|
| `/api/dcim/devices/` | `role`, `name`, `site` | `?role=leaf` |
| `/api/dcim/interfaces/` | `device`, `type`, `name` | `?device=leaf1&type=virtual` |
| `/api/ipam/ip-addresses/` | `device`, `interface`, `vrf` | `?device=leaf1&vrf=gold` |
| `/api/ipam/vlans/` | `vid`, `site`, `group` | `?vid=40` |
| `/api/vpn/l2vpns/` | `type`, `name` | `?type=evpn` |
| `/api/vpn/l2vpn-terminations/` | `l2vpn`, `vlan_id` | `?l2vpn=VLAN40-L2VNI` |
| `/api/plugins/bgp/sessions/` | `device`, `peer_group` | `?device=leaf1` |

### Non-Working Filters (Require Workarounds)

| Endpoint | Invalid Filter | Workaround |
|----------|----------------|------------|
| `/api/ipam/asns/` | `device` | Use custom field `asn` on Device |
| `/api/vpn/l2vpn-terminations/` | `device` | Filter by `vlan_id` then correlate |
| `/api/dcim/interfaces/` | `vrf` | Query IPs with VRF filter, get interface IDs |

---

## Next Steps

1. **Custom Fields Setup** - Create all custom fields listed above in NetBox
2. **Data Population** - Enter fabric topology data into NetBox
3. **NetBox Client** - Update `src/netbox/client.py` to use custom fields
4. **Validation** - Verify data retrieval matches expected fabric config