calulating hosts

jameister

can anyone help me with this please, it's really doing my brain in, i just can't work it out, I'm sure it's very simple but I', really going around in circles here...

for example - say you have a subnet mask of 255.255.0.0 the available hosts are 65,534. How do you work out the hosts?

Thanks in advance before I stop banging my head against a wall!

Jamie

BrizoH

Binary math/powers of 2.

Your formula for working out hosts is 2^n(-2) where n is the number of host bits.

In your example the subnet mask 255.255.0.0 leaves you with 16 host bits (8 bits per octet).

2^16 = 65,536. Minus 2 leaves you with 65,534