subnetting problem.

[Marinski]

I need some help with this subnetting problem here. I think its pretty basic. I just started doing this and i suck at. Can some body who knows how to do this tell me if i'm doing it right?

Heres the problem. It says the number of needed subnets is 750 and the network address is 190.35.0.0.

What i have to answer is---
Address class and number of bits borrowed: (Class B and i borrowed 10 bits)
Total number of subnets and number of usable subnets: ( total subnets is 1024 and usable are 1022)
Total number of addresses and number of usable addresses: (total addresses is 64 and usable is 62 per subnet)
Default and custom subnet mask: (default is 255.255.0.0 and custom is ??255.255.254.192??)

So heres how i broke it down.

190.35.00000000.00|000000 190.35.0.0
190.35.00000000.01|000000 190.35.0.64
190.35.00000000.10|000000 190.35.0.128
190.35.00000000.11|000000 190.35.0.192
190.35.00000001.00|000000 190.35.1.0
etc..

Am i doing this wrong? can somebody that is good at this help?

 

[her209]

512 = 2^9

190.35.0.0/25

 

[Marinski]

Originally posted by: her209
512 = 2^9

190.35.0.0/25

you borrow 9 bits? then its only 512 subnets right? or am i missing something.

 

[her209]

Originally posted by: Marinski

Originally posted by: her209
512 = 2^9

190.35.0.0/25

you borrow 9 bits? then its only 512 subnets right? or am i missing something.

Oh... oops... I misread the number of subnets in the original question. But yes, its 512 subnets - technically, its 510 usable subnets. If you are looking for 750 subnets, then you'd use a subnet mask of 255.255.255.192 or in shorthand form, 190.35.0.0/26.

 

[Marinski]

ok, i got it, thanks. I just wanted to make sure i'm doing it right since the last ?'s i turned in i screwed up.