I have to do a Network Design Project for school, and one of the parts involves assigning IP addresses to each building (6 total). Three days ago I asked my teacher if I was on the right track, and he said he won't tell me but will give me a hint, that one of the IPs I have; is using 32 addresses. And the is using 64. And that it means there are over 200 addresses in the 192.168.25.x network not being used, which isn't an efficient use of address space. I asked him what he meant by that and how is there over 200 addresses, but he hasn't replied since. So now this is really bothering me as I am very confused. How could the IP use 32 addresses, but still have over 200 that are not being used?

What I have

1 Answer 1


Without giving away the answer, will make your assigned subnet have usable addresses from through That leaves - as unused addresses. If you only need 30 addresses for that VLAN, then you should continue to use the rest of the 192.168.25.X range to fulfill the "no wasting" rule of the assignment.

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    That makes sense, is that where the 200 unused IP addresses comes from? Apr 12, 2017 at 19:04
  • Yes, In 192.168.25.X, X ranges from 0-255. a /27 uses 32 addreses, and 256-32=224 Apr 12, 2017 at 19:10

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