wildassmasks...

wild card masks...  i've linked this before but the site below is truly invaluable...

http://www.dslreports.com/faq/15216

my take on it...

128 192 224 240 248 252 254 256
1      1     1     1    1     1     1     1

count em up...

255.255.255.192 = (action in the fourth octet) /26 or 24 + 2 one's
255.255.240.0 = (action in the third) /20 or 16 + 4 one's

ok, we love 256...  256 - 192 = (in the first example) 64
64 minus 1 in the fourth octet =
0.0.0.63  is the wildass

second example; 256 - 240 = 16 -1 or 15 in the third is
0.0.15.255 is the wildass
it's easier to subtract from 256 than 255, and faster... wild...