8/16/2019 Super Easy Subnet Chart

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Bit Value Mask Value # of Bits 2^N-2 # of Bits 2^N-2 # of Bits 2^N-2  

128 128 1 0 9 510 17 131070

64 192 2 2 10 1022 18 262142

32 224 3 6 11 2046 19 524286

16 240 4 14 12 4094 20 10485748 248 5 30 13 8190 21 2097150

4 252 6 62 14 16382 22 4194302

2 254 7 126 15 32766 23 8388606

1 255 8 254 16 65534 24 16777214

Pattern Class Range Default Mask Host Bits

0 A 1-126 255.0.0.0 24

10 B 128-191 255.255.0.0 16110 C 192-223 255.255.255.0 8

1110 D 224-239 Multicast

11110 E 240-247 Experimental

Formulae

256 - Last Non-Zero Value in Subnet Mask = Subnet Bit Increment Value

# of Subnets = 2 ^ N Bits Borrowed **(Possibly -2 if IP SUBNET ZERO not in use.)**

# of Hosts per Subnet = 2 ^ N Bits Remaining -2

Shortcuts for Ranges

1st Valid Host on Subnet = Subnet Address + 1 bit in Last Octet

Last Valid Host on Subnet = Next Subnet Address - 2 bits in Last Octet

Broadcast for Subnet = Next Subnet Address - 1 bit in Last Octet

Super Easy Subnet Chart