How to find Network Bits and Host Bits?
We can find Network Bits and Host Bits from any below information available.
How to find Network Bits and Host Bits from prefix?
Prefix or CIDR Netmask represents network part of IP address.
So, Network Bits = Prefix #
Network Bits and Host Bits together forms 32 bits binary number(Subnet Mask).NB + HB = 32
HB = 32 - NB
Example:
Network Bits and Hostsbits for /23 network
NB = Prefix#
NB = 23
We know that NB + HB = 32
HB = 32 - NB
HB = 32 - 23
HB = 7
Hence for network /23 Network Bits is 23 and Host Bits is 9
How to find Network Bits and Host Bits from Subnet Mask?
As mentioned before Subnet Mask is 32 bits binary number. Which consists of Network Bits and Host Bits.
SM = NB + HB
Convert Subnet Mask in binary format Count consicutive '1' fromMSB Number of consicutive '1' is Network Bits. and Number of consicutive '0' is Host Bits.
Example:
Network Bits and Host Bits for Subnet Mask 255.255.255.128
SM = 11111111.11111111.11111111.10000000
We can write as
SM = 11111111111111111111111110000000
Consicutive '1' from
NB = 1111111111111111111111111 and HB = 0000000
Now simply count number of '1' and number of '0' for Network Bits and Host Bits respectively.
How to find Network Bits and Host Bits from Wildcard Mask?
Wildcard Mask is inverted binary of Subnet Mask.
WM = ~SM
We can say '1' represents Host Bits and '0' represents Network Bits.
Example:
Network Bits and Host Bits from Wildcard Mask 0.0.0.127
WM = 00000000.00000000.00000000.01111111
Now simply count number of '0' and number of '1' for Network Bits and Host Bits respectively.
How to find Netwokbits and Host Bits from Class information?
Classful IP address allocating scheme were designed on basic of predefined block of IP ranges.
Default Network Bits and Host Bits for classes are as below
| Class | Network Bits | Host Bits |
|---|---|---|
| A | 8 | 24 |
| B | 16 | 16 |
| C | 24 | 8 |