It is possible the mask 255.255.231.0 in IPv4?

Question

I have a simple question related with networking, Is it possible to have a mask 255.255.231.0 in IPv4? Why?

Answer 1

Don't think so. The mask should contain all ones followed by all zeros, and 231 is 1110 0111. So the mask would read 11111111.11111111.11100111.00000000.

The valid values are 254, 252, 248, 240, 224, 192, 128 and 0.