Marking prefixes as fully allocated

[ChrisDeh]

Environment

• Python version: 3.8.2
• NetBox version: 2.8.3

Proposed Functionality

Adding an option to a prefix, for marking every IP within this prefix as "in use" - like there is every IP within the prefix created. Especially for IPv6 prefixes were it is impossible to create every IP within a prefix this could be a solution to document the prefix is fully allocated and can't be used. In the prefix-list view, the Utilization Percentage would be shown as 100%, if the option is used.

Use Case

This can be used for example to document IPv6 Prefixes used for DHCP Prefix Delegation to Customers. When speaking about IPv4 Prefixes it is possible to create every IP-Address within a Prefix and define it as "DHCP" - this is not possible with IPv6 cause would decrease netbox Performance massively.

[jeremystretch]

I do want to note that prefix utilization can be calculated in two ways: For container prefixes, it's calculated based on the number and size of child prefixes. For others, it's calculated based on the number of child IP addresses. If implemented, this flag would imply 100% utilization for either case as appropriate.

[v0tti]

I would like to start working on this issue as we need this feature ourself.

As I am not very experienced with Django projects, feedback is very welcome. My current status corresponds to my fork. Should I create a WIP pull request?

An important consideration is with available IP addresses and available prefixes. Should they be returned as available even if this flag is set?

[jeremystretch]

@v0tti No work will be accepted on this issue yet as it is still awaiting milestone assignment.