NetBox

An open source source of truth for network infrastructure that models racks, sites, devices, cables, circuits, tenants, IP addresses and VLANs in one relational data model. It exposes REST and GraphQL APIs for automation, renders device configurations from Jinja2 templates, and offers granular permissions so teams can be scoped to the parts of the network they touch.

Network engineers use it to plan address space, document racks and cabling, and feed inventories into provisioning tools such as Ansible.

Running it internally keeps IP plans and topology details off third-party infrastructure and makes the source of truth easy to snapshot and restore.