[ad#Google Adsense] notation resulting subnet netmask shorthand number of addresses 255.255.255.0 /24 [8-bit] 28 = 256 = 254 hosts + 1 bcast + 1 net base 255.255.255.128 /25 [7-bit] 27 = 128 = 126 hosts + 1 bcast + 1 net base 255.255.255.192 /26 [6-bit] 26 = 64 = 62 hosts + 1 bcast + ...