BGP Data Models

This app adds the following data models to Nautobot:

• AutonomousSystem
• PeeringRole
• BGPRoutingInstance
• AddressFamily
• PeerGroupTemplate
• PeerGroup
• PeerGroupAddressFamily
• PeerEndpoint
• PeerEndpointAddressFamily
• Peering

A key motivation behind this design is the idea that the Source of Truth should take a network-wide view of the BGP configuration rather than a per-device view. This especially applies to the data models for autonomous systems (ASNs), BGP peerings, and network-wide templates (Peer Groups).

The data models introduced by the BGP app support the following Nautobot features:

• Rest API
• GraphQL
• Custom fields
• Custom Links
• Relationships
• Change logging
• Custom data validation logic
• Webhooks

Note

The data models defined in this app were inspired by the Openconfig BGP data model and RFC 9234.

AutonomousSystem

This model represents a network-wide description of a BGP autonomous system (AS). It has fields including the actual AS number (ASN), a description field, foreign key (FK) to a Nautobot Provider object, and a FK to a Nautobot Status object.

PeeringRole

This model operates similarly to Nautobot’s Status and Tag models, in that instances of this model describe various valid values for the Role field used by PeerGroup and Peering records. Similar to those models, this model has fields including a unique name, unique slug, and HTML color code.

BGPRoutingInstance

This model represents a device specific BGP process. It has a mandatory FK to a Nautobot Device, mandatory FK to a AutonomousSystem and following fields:

• Router ID (optional, FK to Nautobot IPAddress)
• Description (optional, string)
• Extra Attributes (optional, JSON)

Extra Attributes

Additional BGP object attributes can be defined in "Extra Attributes" field. Extra attributes are JSON type fields meant to store data defined by the user.

Extra attributes follow the inheritance pattern, thus allowing for the merging of the inherited extra attributes.

Example of the extra attributes:

{"ttl-security": 1, "timers": [6, 20] }

Extra Attributes are available for following models:

• BGPRoutingInstance
• AddressFamily
• PeerGroupTemplate
• PeerGroup
• PeerGroupAddressFamily
• PeerEndpoint
• PeerEndpointAddressFamily

AddressFamily

This model represents configuration of a BGP address-family (AFI-SAFI). AddressFamily aims to represent a device specific Address Family instance.

It has a locally unique AFI (address family identifier) field, optional VRF field (FK to Nautobot VRF) and following fields:

• Import Policy (optional, string)
• Export Policy (optional, string)

(*) The network-wide modeling of AddressFamilies will be implemented in the future with AddressFamilyTemplate model similar to the PeerGroupTemplate.

PeerGroupTemplate

This model represents a network-wide configuration for PeerGroups. PeerGroupTemplate aims to represent a global configuration, and it has a mandatory Name field, and the following fields:

• ASN (optional, FK to AutonomousSystem)
• Role (optional, FK to PeeringRole)
• Description (string)
• Enabled (bool)
• Secret (optional, FK to Nautobot Secret)
• Extra Attributes (optional, JSON)

PeerGroup

This model represents a common configuration for a group of functionally related BGP peers. Peer Group aims to represent device-specific configuration shared across multiple peerings, and it has a mandatory Name field, optional FK to a network-wide PeerGroupTemplate, and additional fields including

• ASN (optional, FK to AutonomousSystem)
• Source IP (optional, FK to Nautobot IPAddress, mutually-exclusive with Source Interface)
• Source Interface (optional, FK to Nautobot Interface, mutually-exclusive with Source IP)
• Role (optional, FK to PeeringRole)
• Description (string)
• Enabled (bool)
• Secret (optional, FK to Nautobot Secret)
• Extra Attributes (optional, JSON)

PeerGroupAddressFamily

This model represents address-family-specific configuration of a PeerGroup. It has a mandatory FK to a PeerGroup and a mandatory afi_safi field, and additional fields including

• Import Policy (optional, string)
• Export Policy (optional, string)
• Extra Attributes (optional, JSON)

PeerEndpoint

PeerEndpoint records are created when the Peering instance is created.

This model represents the configuration of a single device for a single BGP peering.

Note that in the case of an external peering (connection with an ISP or Transit Provider), there is no need to create and model the provider's Device object. However, as a minimum PeerEndpoint (representing the provider's side of Peering) created during Peering object creation, will have to store IP Address and ASN.

PeerEndpoint model has a mandatory FK to a BGP Routing Instance (BGPRoutingInstance) record, an optional foreign-key relationship to a PeerGroup, and additional keys including:

• ASN (optional, FK to AutonomousSystem)
• Peer (optional, FK to PeerEndpoint)
• Source IP (optional, FK to Nautobot IPAddress, mutually-exclusive with Source Interface)
• Source Interface (optional, FK to Nautobot Interface, mutually-exclusive with Source IP)
• Role (optional, FK to PeeringRole)
• Description (string)
• Enabled (bool)
• Secret (optional, FK to Nautobot Secret)
• Extra Attributes (optional, JSON)

PeerEndpoint Local-IP

To ease the data presentation and consumption, PeerEndpoint provides a property named local_ip.

The value of this property will be presented in the app's Graphical User Interface (GUI) and can be used to render configuration templates.

As Source-IP and Source-Interface could be defined at multiple inheritance levels, each Peer Endpoint will have a local_ip determined based on the following order:

1. PeerEndpoint's source_ip attribute (if exists)
2. PeerGroup's source_ip attribute (if exists)
3. PeerEndpoint's source_interface attribute (if exists)
4. PeerGroup's source_interface attribute (if exists)

PeerEndpointAddressFamily

This model represents address-family-specific configuration of a device's PeerEndpoint. It has a mandatory FK to a PeerEndpoint and a mandatory afi_safi field, and additional keys including:

• Import Policy (optional, string)
• Export Policy (optional, string)
• Extra Attributes (optional, JSON)

Peering

This model represents the shared configuration of a single BGP peer relationship between two endpoints. It has FKs to two PeerEndpoint records (representing the two devices involved in the peering), and additional fields including:

• Status (FK to Nautobot Status)

Note

The classification of a session as BGP "internal" or "external" is useful in the construction of queries and filters but does not need to be stored as an actual database attribute (as it is implied by whether the ASNs of the two BGPPeerEndpoints involved are identical or different). It is implemented as a derived property of the Peering model.

Inheritance between models

Some models can inherit attribute values, similar to what BGP supports with Peer Group. The inheritance is built hierarchically. The final attribute value will be taken from the first object in the hierarchy, moving from the top, which has given the attribute value defined.

Example PeerEndpoint inheritance details:

• A PeerEndpoint inherits AutonomousSystem and extra_attributes fields from:

  • PeerGroup
  • PeerGroupTemplate
  • BGPRoutingInstance

• A PeerEndpoint inherits description, enabled, export_policy, import_policy fields from:

  • PeerGroup
  • PeerGroupTemplate

• A PeerEndpoint inherits source_ip, source_interface fields from:

  • PeerGroup

As an example, a PeerEndpoint associated with a PeerGroup will automatically inherit the above attributes of the PeerGroup that haven't been defined at the PeerEndpoint level. If an attribute is defined at both levels, the value defined in the PeerEndpoint will be used.

The inherited values will be automatically displayed in the UI and can be retrieved from the REST API by adding ?include_inherited=true parameter.

Warning

BGP models Custom Fields and GraphQL currently does not offer support for BGP Field Inheritance. See GraphQL issue #43 for details.

Following is the complete documentation of the field inheritance hierarchy. Models are ordered with the topmost having the highest priority. The first model with an assigned attribute value will be used as an inheritance source.

PeerEndpoint:

Attribute	Inheritance from model
autonomous_system	PeerGroup → PeerGroupTemplate → BGPRoutingInstance
extra_attributes	PeerGroup → PeerGroupTemplate → BGPRoutingInstance
description	PeerGroup → PeerGroupTemplate
enabled	PeerGroup → PeerGroupTemplate
export_policy	PeerGroup → PeerGroupTemplate
import_policy	PeerGroup → PeerGroupTemplate
role	PeerGroup → PeerGroupTemplate
source_ip	PeerGroup
source_interface	PeerGroup

PeerGroup:

Attribute	Inheritance from model
extra_attributes	PeerGroupTemplate → BGPRoutingInstance
autonomous_system	PeerGroupTemplate
description	PeerGroupTemplate
enabled	PeerGroupTemplate
export_policy	PeerGroupTemplate
import_policy	PeerGroupTemplate
role	PeerGroupTemplate

PeerGroupAddressFamily:

Attribute	Inheritance from model
extra_attributes	AddressFamily (same afi_safi only)

PeerEndpointAddressFamily:

Attribute	Inheritance from model
extra_attributes	PeerGroupAddressFamily (same afi_safi only) → AddressFamily (same afi_safi only)
import_policy	PeerGroupAddressFamily (same afi_safi only)
export_policy	PeerGroupAddressFamily (same afi_safi only)
multipath	PeerGroupAddressFamily (same afi_safi only)