IP Subnet (Anyone able to help me with my assignment?) hehe online, understand, calculator, studying

et1984

Sorry I just started studying IP subnetting and VLSM
I have a few questions for subnetting, just wondering if someone can give me a hand ^_^
this is what I have to do..

• The     entire class “A” address 10.0.0.0 uses a class “C” subnet mask. How many     valid subnets are available and how many hosts are supported?

I know using online subnet calculator should work but instead of using such thing I rather understand how to calculate it step by step.  I got this as my own answer but I'm not sure if it is right "256 subnets and 254 hosts"

The professionals can you give me a hand? ^_^ thanks

mcjohnjohn

65536 subnets and 254 hosts for each subnet

et1984

65536 subnets and 254 hosts for each subnet
mcjohnjohn 發表於 2012-2-14 22:53

how did 65536  being calculated? mind giving me an idea if it's too much to write?

Prelude

256 * 256?

Prelude

10.xxx.xxx.yyy

yyy are the available hosts for xxx.xxx subnet.
there are only 256 in each octet => 256 different yyy's.
xxx.xxx = 256 x 256.

mcjohnjohn

how did 65536  being calculated? mind giving me an idea if it's too much to write?
et1984 發表於 2012-2-15 15:12

example class A: 10.x.x.x
example class C: 10.0.0.x
as a result, 1 class A = 256*256 = 65536 class C
for each subnet, the first and last IP addresses are reserved, so each subnet can have 256-2 = 254 hosts

sorry for my laziless in previous post.

et1984

I think I get it....so if it's a class A 10.0.0.0 with a class b mask then it'll be reversed 254*254 hosts and 256 subnets?

arg I shouldn't take database and network at the same thing I kept on thinking of my ERD at this moment because I have a project to hand in tomorrow but my network homework needed to be handed in the day after

Thanks a lot guys hopefully I didn't annoy you guys if I didn't fully understand and kept on asking.

et1984

ah...so there's no complicated calculation like 2 to the power of how many host and net bits just simple calculations between the octets.

mcjohnjohn

I think I get it....so if it's a class A 10.0.0.0 with a class b mask then it'll be reversed 254*254 ...
et1984 發表於 2012-2-15 17:50

if class A -> class B, it should be:
1. 256 subnet
2. 256*256 - 2 hosts =  65534 (Not 254*254)

et1984

ah ! right! thanks thanks....sigh just a simple mistake will ruin the whole network....