offset parameter for endpoint /ipam/prefixes/{id}/available-ips/

[cocomundo]

hello,

i'm currently trying to query available IPs from a /16 network and tried using the offset parameter for the endpoint /ipam/prefixes/{id}/available-ips/ but it seems the parameter does not exist or does not work (or i just don't know how to use the API endpoint)

I am using the latest version
# nautobot-server --version Nautobot version: 2.4.5 Django version: 4.2.20

I tried the following querys, but it always falls back to using no offset and also does not tolerate the limit of 20.

curl -k -H "Authorization: Token <token>" -H "Accept: application/json; charset=UTF-8" https://10.0.0.45/api/ipam/prefixes/5236f93d-eb94-4510-9938-37504e588d20/available-ips/?offset=10&limit=20

curl -k -H "Authorization: Token <token>" -H "Accept: application/json; charset=UTF-8" https://10.0.0.45/api/ipam/prefixes/5236f93d-eb94-4510-9938-37504e588d20/available-ips/?offset=10

The documentation thats shipped in this version tells me that the parameter exists but i can't manage to make it work.
The Prefix exists and i do get the first 50 available ip entrys.

Any tips or does someone see my mistake?

[glennmatthews]

I don't think the offset parameter is supported by this endpoint, probably there's a bug in the documentation. limit should work though.

I'm honestly curious - what's your use case for using offset with this API?

[cocomundo]

what we actually want is a (DHCP) range, i.e. I ask the API which ip addresses are available in a certain range in a prefix.
e.g.
we've got the subnet 192.168.0.0/16 , and want all available ip addresses in the range
192.168.200.0 - 192.168.201.0 in the prefix.
AFAICT this requires an offset parameter or do you know another way around?
In netbox there is support for ranges [0] but i assume it was removed since the fork?

[0] https://netboxlabs.com/docs/netbox/en/stable/models/ipam/iprange/

[glennmatthews]

An alternative could maybe be to create 192.168.200.0/24 as a Pool prefix and allocate IPs directly from that pool?

[cocomundo]

AFAICT It could work, but it would lead to more complexity, as prefixes always correspond to powers of two while DHCP ranges are not necessarily powers of two. In addition, when searching you also run into the problem that you can query a maximum of 1000 pages and with really large DHCP ranges you would have to create (and remove) many “small” prefixes. But it could still work i think, so thanks for the suggestion.

In your opinion, would there be anything against implementing an offset parameter upstream (Does not mean you would have to implement it)?

[glennmatthews]

I think a pull request to add support would be welcomed, yes.

[ChrisDeh]

I'd like to bring up that it could be an option to move the IP Ranges, known from the security app, to the core ipam. This would also solve some other issues we currently face to migrate an existing IPAM to nautobot as we have to handle non CIDR expressable IP Ranges for things like DHCP Pools.