I'm trying to understand subnet masks. I was given the question below and chose the answer of **/30** since it seems that each subnet needs only one host IP. **/31** was not a possible answer. However, the answer is **/29.** Can anyone clarify why that is correct?

"Which of the following would the security engineer set as the subnet mask for the servers below to utilize host addresses on separate broadcast domains?"

```
Server 1: 192.168.100.6 
Server 2: 192.168.100.9 
Server 3: 192.169.100.20

```