I think , how to find network number is very basic knowledge of computer network but I don’t remember. However, after I reviewed my notebook training , I found it again.
These are solution :
1. Convert IP Address to binary number ,
192.168.0.1 => 1100 0000 . 1010 10000 . 0000 0000 . 0000 0001
2. Convert Broadcast IP to binary number ,
255.255.255.0 => 1111 1111 . 1111 1111 . 1111 1111 . 0000 0000
3. Bring binary IP Address operate with Broadcast IP by AND operation,
1100 0000 . 1010 1000 . 0000 0000 . 0000 0001
and
1111 1111 . 1111 1111 . 1111 1111 . 0000 0000
=
1100 0000 . 1010 1000 . 0000 0000 . 0000 0000
4. Convert this result to decimal number.
192 . 168 . 0 . 0 <= This is Network number.