Next Available VLAN option

[kollross]

Similar to the green boxes used to show gaps in a series of IP address (pictured). It would be awesome to have some visual representation where there are gaps in Vlan IDs.

[pheus]

Good news, NetBox already supports this.

Create a VLAN Group, add your VLANs to it, and the group view makes it easy to see which VLAN IDs are in use and which are available. 🙂

[kollross]

Thank you, that is handy. Any tricks to doing the same for Prefixes. I may have to write something, but it would be awesome if you could say "show me all the available /19 (or /23, /27, etc).

[pheus]

Glad that helped!

For prefixes, you can create a parent container prefix (status container). The prefix view will show the free child space under it, so you can see where the gaps are.

If you’re automating, NetBox can allocate the next available child prefix of a given length from a parent via the API:

REST API

POST /api/ipam/prefixes/{parent_id}/available-prefixes/
Content-Type: application/json

{
  "prefix_length": 19,        // e.g., ask for the next available /19
  "status": "active"          // optional: set status on creation
}

This call creates (and returns) the next available child prefix of the requested length under the parent

Hope that helps!