@philips If we need a negative one, I prefer not having one. 
I hope we can help people avoid making mistake. 
For example:
When we have a machine A with IP 10.10.10.1
If people add a new machine accidentally with same name but different IP, we will replace the existing machine with a new one. 

This is a tradeoff, when we give people more flexibility we give them more chances to make mistakes.