How to Subnet Your Network

Base Network Number/mask		(for example, 38.242.251.0/24) See KEY below for more examples
Desired #of segments	2 4 8 16 32 64 128 256	You may only generate 2^n subnets.
Internet Router Model	-- Router Not Listed -- ASCEND_PIPELINE CISCO COMPATIBLE_SYSTEMS-OLD COMPATIBLE_SYSTEMS-OS4.X FARALLON/NETOPIA LIVINGSTON PROTEON/GLOBETROTTER ROCKWELL/NETHOPPER	If router type is not listed, general instructions will be provided.
Which segment will the Internet router be on?		1 being the lowest segment
Internal Routing Method	Static Routes RIP

KEY
Each octet, 8 ones, equals 255 in binary:

128+64+32+16+08+04+02+01= 255
 1  1  1  1  1  1  1  1= 8

255.255.0.0 = /16
|   8    ||   8    ||   0    ||   0    |
[ 11111111  11111111  00000000  00000000 ]

255.255.255.0 = /24
|   8    ||   8    ||   8    ||   0    |
[ 11111111  11111111  11111111  00000000 ]

255.255.255.128 = /25
|   8    ||   8    ||   8    ||   1    |
[ 11111111  11111111  11111111  10000000 ]

255.255.255.192 = /26
|   8    ||   8    ||   8    ||   2    |
[ 11111111  11111111  11111111  11000000 ]

255.255.255.224 = /27
|   8    ||   8    ||   8    ||   3    |
[ 11111111  11111111  11111111  11100000 ]

255.255.255.240 = /28
|   8    ||   8    ||   8    ||   4    |
[ 11111111  11111111  11111111  11110000 ]