Why is it very useful to
be able to know that 255 - 0, 255 - 1, 255 - 3, 255 - 7, 255 - 15, 255 -
31,
255 - 63, 255 - 127 and 255 - 255 are those 9 numbers.
What do all of the above numbers have in common when you write them
in binary? Especially 254, 252, 248, 240, 224, 192 and 128 seen in
binary!
What do 1, 3, 7, 15, 31, 63, and 127 all have in common?
If the subnet mask is 255.255.252.0 the in binary, each octet expands and the subnect mask looks like this: 255.255.252.0 is 11111111.11111111.11111100.00000000 ******** ******** ------