All error codes

network_in_use

HTTP 409 Servers are still attached to this network

What happened

Servers are still attached to this network, and you asked to delete it or to change its subnet. Either would cut those servers off.

What to do

Detach the servers first - move their interfaces to another network, or delete the servers - and then repeat the same request.

Retrying

Change the state this refers to, then repeat the same request with the same idempotency key.

How it arrives

{
    "type": "https://docs.fiberax.com/errors/network_in_use",
    "title": "Servers are still attached to this network",
    "status": 409,
    "code": "network_in_use",
    "request_id": "a277dcd1ca652c65"
}

Branch your code on code, never on the wording of title.