SUBNETTING
Increasing the number of network bits and decreasing the
number of host bits is called subnetting.
Class C: In class c
we can subnet from 1 to 6.
One bit
subnetting: 192.168.0.00000000/25 mask: 255.255.255.128
Total subnets: 21=2. Total host in each subnet: 27-2=126.
We minus last subnet mask value from 256 to find next subnet
id. Ex: 256-128=128. Or Network id+ total host= last IP.
Two bits
subnetting: 192.168.0.00000000/26 mask: 255.255.255.192
Total subnets: 22=4. Total host in each subnet: 26-2=62.
Three bits
subnetting: 192.168.0.00000000/27 mask: 255.255.255.224
Total subnets: 23=8. Total host in each subnet: 25-2=30.
Four bits
subnetting: 192.168.0.00000000/28 mask: 255.255.255.240
Total subnets: 24=16. Total host in each subnet: 24-2=14.
Five bits
subnetting: 192.168.0.00000000/29 mask: 255.255.255.248
Total subnets: 25=32. Total host in each subnet: 23-2=6.
Six bits
subnetting: 192.168.0.00000000/30 mask: 255.255.255.252
Total subnets: 26=64. Total host in each subnet: 22-2=2.
Class B: In class b
we can subnet from 1 to 14.
One bit
subnetting: 172.16.00000000.0/17 mask: 255.255.128.0
Total subnets: 21=2. Total host in each subnet: 215-2=32766.
Two bits
subnetting: 172.16.00000000.0/18 mask: 255.255.192.0
Total subnets: 22=4. Total host in each subnet: 214-2=16382.
Three bits
subnetting: 172.16.00000000.0/19 mask: 255.255.224.0
Total subnets: 23=8. Total host in each subnet: 213-2=8190.
Four bits
subnetting: 172.16.00000000.0/20 mask: 255.255.240.0
Total subnets: 24=16. Total host in each subnet: 212-2=4094.
Five bits
subnetting: 172.16.00000000.0/21 mask: 255.255.248.0
Total subnets: 25=32. Total host in each subnet: 211-2=2046.
Six bits
subnetting: 172.16.00000000.0/22 mask: 255.255.252.0
Total subnets: 26=64. Total host in each subnet: 210-2=1022.
Seven bits
subnetting: 172.16.00000000.0/23 mask: 255.255.254.0
Total subnets: 27=128. Total host in each subnet:
29-2=510.
Eight bits
subnetting: 172.16.00000000.0/24 mask: 255.255.255.0
Total subnets: 28=256. Total host in each subnet:
28-2=254.
Nine bits
subnetting: 172.16.0.00000000/25 mask: 255.255.255.128
Total subnets: 29=512. Total host in each subnet:
27-2=126.
Ten bits
subnetting: 172.16.0.00000000/26 mask: 255.255.255.192
Total subnets: 210=1024. Total host in each
subnet: 26-2=62.
Eleven bits
subnetting: 172.16.0.00000000/27 mask: 255.255.255.224
Total subnets: 211=2048. Total host in each
subnet: 25-2=30.
Twelve bits
subnetting: 172.16.0.00000000/28 mask: 255.255.255.240
Total subnets: 212=4094. Total host in each
subnet: 24-2=14.
Thirteen
bits subnetting:172.16.0.00000000/29 mask: 255.255.255.248
Total subnets: 213=8192. Total host in each
subnet: 23-2=6.
Fourteen bits subnetting:172.16.0.00000000/30
mask: 255.255.255.252
Total subnets: 214=16384. Total host in each
subnet: 22-2=2.
Class A:
In class A we can subnet from 1 to 22.
One bit
subnetting: 10.00000000.0.0/9 mask: 255.128.0.0
Total subnets: 21=2. Total host in each subnet: 223-2=8388606.
Two bits
subnetting: 10.00000000.0.0/10 mask: 255.192.0.0
Total subnets: 22=4. Total host in each subnet: 222-2=4194302.
Three bits subnetting: 10.00000000.0.0/11
mask: 255.224.0.0
Total subnets: 23=8. Total host in each subnet: 221-2=2097150.
Four bits
subnetting: 10.00000000.0.0/12 mask: 255.240.0.0
Total subnets: 24=16. Total host in each subnet: 220-2=1048574.
Five bits
subnetting: 10.00000000.0.0/13 mask: 255.248.0.0
Total subnets: 25=32. Total host in each subnet: 219-2=524286.
Six bits
subnetting: 10.00000000.0.0/14 mask: 255.252.0.0
Total subnets: 26=64. Total host in each subnet: 218-2=262142.
Seven bits
subnetting: 10.00000000.0.0/15 mask: 255.254.0.0
Total subnets: 27=128. Total host in each subnet:
217-2=131070.
Eight bits
subnetting: 10.00000000.0.0/16 mask: 255.255.0.0
Total subnets: 28=256. Total host in each subnet:
216-2=65534.
Nine bits
subnetting: 10.0.00000000.0/17 mask: 255.255.128.0
Total subnets: 29=512. Total host in each subnet:
215-2=32766.
Ten bits
subnetting: 10.0.00000000.0/18 mask: 255.255.192.0
Total subnets: 210=1024. Total host in each
subnet: 214-2=16382.
Eleven bits
subnetting: 10.0.00000000.0/19 mask: 255.255.224.0
Total subnets: 211=2048. Total host in each
subnet: 213-2=8190.
Twelve bits
subnetting: 10.0.00000000.0/20 mask: 255.255.240.0
Total subnets: 212=4096. Total host in each
subnet: 212-2=4094.
Thirteen
bits subnetting:10.0.00000000.0/21 mask: 255.255.248.0
Total subnets: 213=8192. Total host in each
subnet: 211-2=2046.
Fourteen
bits subnetting:10.0.00000000.0/22 mask: 255.255.252.0
Total subnets: 214=16384. Total host in each
subnet: 210-2=1022.
Fifteen bits
subnetting:10.0.00000000.0/23 mask: 255.255.254.0
Total subnets: 215=32768. Total host in each
subnet: 29-2=510.
Sixteen
bits subnetting:10.0.00000000.0/24 mask: 255.255.255.0
Total subnets: 216=65536. Total host in each
subnet: 28-2=254.
Seventeen
bits subnetting:10.0.0.00000000/25 mask: 255.255.255.128
Total subnets: 217=131072. Total host in each
subnet: 27-2=126.
Eighteen
bits subnetting:10.0.0.00000000/26 mask: 255.255.255.192
Total subnets: 218=262144. Total host in each
subnet: 26-2=62.
Nineteen
bits subnetting:10.0.0.00000000/27 mask: 255.255.255.224
Total subnets: 219=524288. Total host in each
subnet: 25-2=30.
Twenty bits
subnetting: 10.0.0.00000000/28 mask: 255.255.255.240
Total subnets: 220=1048576. Total host in each
subnet: 24-2=14.
Twenty one bits subnetting:10.0.0.00000000/29
mask: 255.255.255.248
Total subnets: 221=2097152. Total host in each
subnet: 23-2=6.
Twenty two bits subnetting:10.0.0.00000000/30 mask:
255.255.255.252
Total
subnets: 222=4194304. Total host in each subnet: 22-2=2.