this post was submitted on 27 Nov 2023
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IPAM, vRA, APIs, oh my (real.lemmy.fan)
submitted 9 months ago* (last edited 9 months ago) by [email protected] to c/[email protected]
 

Hi all. I'm not ready to die on this hill, but I am willing to suffer some serious injuries.

Here's the question: Should an IPAM product hand out static IPs when called upon by API for next available address?

Say I setup a machine on vRA using API calls to an enterprisey-IPAM solution using their documented API to poll, and perhaps subsequently pull, the next available IP address.

The API assigns an IP, but the IP assigned is the next IP available in a static range, not an IP address in an established and advertised DHCP range. Thus, any of a number of reserved static IPs will be dynamically assigned via API. The API is not using the IPAM product's built-in DHCP server to dynamically assign addresses. The IPAM product's DHCP and DNS are authoritative.

Bug, or feature?

As an engineer, my take is that the API calls should always pull from DHCP. Static IPs must be considered to be reserved, even if marked unused in IPAM, and should never be assigned whereas DHCP keeps records of IPs assigned and can be trusted to hand out an IP not being used. The idea is, when a new machine is brought online and gets an IP, that machine can either retain the DHCP-assigned addresses or I can assign it a static IP if necessary. Never, ever should my IPAM product think it is OK to hand out a ~~private~~ static IP address.

I can see how some people flip this and want their DHCP pools to be untouched by IPAM, but that's just backwards in my eyes.

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[–] [email protected] 2 points 9 months ago (1 children)

I would consult the documentation for what exactly it means by a request for "next available IP".

I feel like if you want addresses assigned from DHCP, just use DHCP.

[–] [email protected] 1 points 9 months ago (1 children)

API calls are used when automating or scripting because some environments/subnets may not have DHCP available.

[–] [email protected] 2 points 9 months ago

Well, if you're doing static assignments because there's no DHCP, then it makes sense to not use the DHCP range.