# Help !

Registered Users Posts: 1 ■□□□□□□□□□
Help! i doesn't know how to do this question.
192.168.25.0 , approximately 55 nodes per subnet. How i know the number of hosts per subnet?

• Member Posts: 2,394 ■■■■■■■■□□
So you know that your bit increments are 1, 2, 4, 8, 16, 32, 64, 128. There are 8 bits in each octet representing the former numbers. The subnet has to be in increments of one of those numbers, so which we would use? 32 and anything under is too small, 128 is too large, so we'd use a 64 bit increment.

Assuming your subnet mask for 192.168.25.0 is 255.255.255.0 you would use the first two bits in that last octet. 128+64 = 192. So your subnet mask would be 255.255.255.192. Your first subnet would look like

192.168.25.0 - 192.168.25.63
192.168.25.64 - 192.168.25.127
etc.

This would allow for 62 hosts per subnet (64 minus two because one is your network and one is your broadcast).
• x+y = 8
2^y-2 = 55 therfore 2^y>57
in this situation the answer for Y is 6, 2^6 = 64 and the number for subnets would be 2^x, therefor the subnets are 2^2 = 4