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Architecture

Internally the network-importer is leveraging the diffsync library to compare the state of the network and the state of the Source of Truth. The diffsync library is designed to compare the state of 2 adapters based on a shared data-models.

To communicate to the network devices, the network importer is leveraging Nornir and incorporate a concept of drivers to easily add support for more platforms if needed. By default the Network Importer supports 3 main actions to execute against the network devices:

  • get_config: Retrieve the running configuration and store it in the config_directory folder.
  • get_neighbors: Retrieve the list of all neighbors, either from LLDP or CDP (based on the configuration)
  • get_vlans: Retrieve the list of vlans present on the device.

Internal Datamodel

The internal/shared datamodel is defined in the network_importer/models.py file. Currently the following models are defined

  • Site
  • Device
  • Interface
  • IP address
  • Prefix
  • Vlan
  • Cable

It's possible to extend the default models and add your own, please check the extensibility section of the documentation

Backend, Adapters & Inventory

To operate the Network Importer needs 1 inventory and 2 adapters:

  • An inventory to get the list of devices to analyze and get the minimum information to connect to them (platform, address, cred entials ..)
  • One adapter to read the information from the network and one to read/write information to the Source of Truth backend.

Since the inventory is usually leveraging the SOT, the SOT adapter and the inventory are packaged into a backend. Both Nautobot and Netbox are supported as backend systems. When a specific backend is selected it will update both the SOT adapter and the inventory. With or without leveraging the default backends, it's possible to provide your own adapter or extend one of the default adapters.

The base adapter for Network Importer is defined in network_importer/adapters/base.py. The main difference with a standard diffsync adapter is that a Network Importer adapter needs to accept a NetworkImporter inventory (based on a Nornir inventory) as parameters at init time (nornir).

Nautobot API Adapter

The Nautobot API adapter is designed to read the status of a Nautobot server over its Rest API and update Nautobot based on the status of the network.

The table below present the capabilities in term of : Read, Create, Update and Delete supported for each model by the netbox_api adapter.

Model Inherit from Create Read Update Delete
NautobotSite Site No Yes No No
NautobotDevice Device No Yes No No
NautobotInterface Interface Yes Yes Yes Yes
NautobotIPAddress IPAddress Yes Yes Yes Yes
NautobotPrefix Prefix Yes Yes Yes No
NautobotVlan Vlan Yes Yes Yes No
NautobotCable Cable Yes Yes No No

It's possible to extend the default models and add your own, please check the extensibility section of the documentation

NetBox API Adapter

The NetBox API adapter is designed to read the status of a NetBox server over its Rest API and update NetBox based on the status of the network.

The table below present the capabilities in term of : Read, Create, Update and Delete supported for each model by the netbox_api adapter.

Model Inherit from Create Read Update Delete
NetboxSite Site No Yes No No
NetboxDevice Device No Yes No No
NetboxInterface Interface Yes Yes Yes Yes
NetboxIPAddress IPAddress Yes Yes Yes Yes
NetboxPrefix Prefix Yes Yes Yes No
NetboxVlan Vlan Yes Yes Yes No
NetboxCable Cable Yes Yes No No

It's possible to extend the default models and add your own, please check the extensibility section of the documentation

Network Importer Adapter

The Network Importer Adapter is designed to read the status of the network primarily from Batfish but it can also leverage Nornir to gather some additional information like the list of LLDP/CDP neighbors or the list of vlans.

Drivers

The communicate with the network devices, the network-importer is leveraging Nornir and support some drivers per platform to easily support more device type.

Each driver, should support each of the following actions:

  • get_config: Retrieve the running configuration and store it in the config_directory folder.
  • get_neighbors: Retrieve the list of all neighbors, either from LLDP or CDP (based on the configuration)
  • get_vlans: Retrieve the list of vlans present on the device.

By default, 4 drivers are available default, cisco_default, juniper_junos & arista_eos and the mapping between a platform and the specific driver can be defined in the configuration. By default the 5 most common platforms are mapped to the following drivers.

Platform Driver
all default
cisco_nxos cisco_default
cisco_ios cisco_default
cisco_xr cisco_default
juniper_junos juniper_junos
arista_eos arista_eos

The name of the platform must match the name of the slug platform defined in the inventory for a given device

Drivers available by default

Each driver can implement an action using the connection of its choice. The table below present how each driver shipping with the network importer are implemented.

Driver get_config get_neighbors get_vlans
default Napalm Napalm Not Supported
default_cisco Netmiko Netmiko + Genie Netmiko + Genie
juniper_junos default default Not Supported
arista_eos default default Napalm + eAPI

The name of the Napalm driver for each device must be defined in Netbox as part of the platform definition.