I have then tried to readd the device, but now I get a KeyError. I've tried to add the device with a new name (that was not in DNS) and then reset the IP to the IP of the old device, and apparently it is the IP that is causing the error.

I've seen this in the event.log:

2016-01-21T11:07:45 ERROR zen.Zuul 'hostname'
Traceback (most recent call last):
  File "/opt/zenoss/Products/Zuul/routers/device.py", line 651, in resetIp
    info.ipAddress = ip  # Set to empty causes DNS lookup
  File "/opt/zenoss/Products/Zuul/infos/device.py", line 200, in setIpAddress
    msg = self._object.setManageIp(ip)
  File "/opt/zenoss/Products/ZenModel/Device.py", line 950, in setManageIp
    if self._isDuplicateIp(ip):
  File "/opt/zenoss/Products/ZenModel/Device.py", line 906, in _isDuplicateIp
    dev = ipMatch.device()
  File "/opt/zenoss/Products/ZenModel/IpAddress.py", line 234, in device
    if iface: return iface.device()
  File "/opt/zenoss/Products/ZenModel/OSComponent.py", line 46, in device
    if os: return os.device()
  File "/opt/zenoss/Products/ZenModel/OperatingSystem.py", line 158, in device
    return self.getPrimaryParent()
  File "/opt/zenoss/Products/ZenRelations/PrimaryPathObjectManager.py", line 83, in getPrimaryParent
    return self.__primary_parent__.primaryAq()
  File "/opt/zenoss/Products/ZenRelations/PrimaryPathObjectManager.py", line 78, in primaryAq
    raise KeyError(self.id)
KeyError: 'hostname'
I've tried to navigate to the IP in question (via Infrastructure -> Networks) and I then get a yellow popup with "KeyError 'hostname'"

Even with the device deleted and no device named "hostname" am I able to browse the subnet.

I've run zodbscan, it doesn't throw any errors regarding this.

I've run zennetworkclean, and it says all networks are fine

I've run findposkeyerror and it doesn't say that there are any errors.

I tried via zendmd to:

>>> d=find('hostname-on-same-subnet-as-defective-ip')
>>> ipMatch = d.getNetworkRoot().findIp("defective-ip")
>>> ipMatch.device()
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/opt/zenoss/Products/ZenModel/IpAddress.py", line 234, in device
    if iface: return iface.device()
  File "/opt/zenoss/Products/ZenModel/OSComponent.py", line 46, in device
    if os: return os.device()
  File "/opt/zenoss/Products/ZenModel/OperatingSystem.py", line 158, in device
    return self.getPrimaryParent()
  File "/opt/zenoss/Products/ZenRelations/PrimaryPathObjectManager.py", line 83, in getPrimaryParent
    return self.__primary_parent__.primaryAq()
  File "/opt/zenoss/Products/ZenRelations/PrimaryPathObjectManager.py", line 78, in primaryAq
    raise KeyError(self.id)
KeyError: 'hostname'


Somebody has hints to how I can cleanup the IPs so I can reuse this particular IP?