WILCARD MASK + INVERS OF SUBNET MASK

Example #1

/24: 255.255.255.0

255 - 255 = 0
255 - 0 = 255


Inverse /24: 0.0.0.255

Example #2

/27: 255.255.255.224

255 - 255 = 0
255 - 224 = 31


Inverse /27: 0.0.0.31

Example #3

/30: 255.255.255.252

255 - 255 = 0
255 - 252 = 3


Inverse /30: 0.0.0.3