subnetting (helps security)

I am studying subnetting and I have a few question, if you do not mind.

1. why will the network number be 0 if we borrow just 1 bit?

2. is my table correct?
Usable Sub/Hosts (Total S/hosts - 2)

62
30
14
6
2



Total Sub/ hosts (256 - Sub/mask)

64
32
16
8
4



Subnet Mask (add bits values)

192
224
240
248
252



Bits Values
128
64
32
16
8
4
2
1

Borrowed bits Power

2
3
4
5
6




2
2
2
2
2



Total subnets

4
8
16
32
64



Usable subnets

2
6
14
30
62





3. why is the total number of subnet hosts the same as the last borrowed
bit's value?
4. why is the max number of subnets equal to the number 2 powered by the
number of the borrowed bits?
5. why do we use the ANDing method to find out if a certain IP address is
within a subnet?

Thanks in advance!

new guy :)



.

Relevant Pages

  • Re: Subnetting problem
    ... >I had a problem where I'm supposed to find subnets using the equation 2n-2> with n being the number of bits I borrow from the original subnet mask. ... > wanted to borrow 3 bits, using traditional algebra it would be 2-2 ...
    (microsoft.public.cert.exam.mcse)
  • Re: Subnetting problem
    ... with n being the number of bits I borrow from the original subnet mask. ... equals 4 (subnets). ... IP and one is a broadcast IP neither of which can be assigned to a host. ...
    (microsoft.public.cert.exam.mcse)
  • Re: Subnetting problem
    ... There probably are some routers out there that still cling to this, but I doubt you'll ever see one in a production environment. ... But if you're taking a test that is testing yor knowledge of classful subnets, the correct answer to your example is 6 subnets. ... >I had a problem where I'm supposed to find subnets using the equation 2n-2> with n being the number of bits I borrow from the original subnet mask. ...
    (microsoft.public.cert.exam.mcse)
  • Re: Anonymizing Packets yet ensuring 0 % packet loss
    ... exercise of mine is to by pass the security systems in place & prove ... you need anything that needs a reply from the network, ... We do not want the administration to say that " we could have stopped ... enumerate the services, administration subnets, department subnets, ...
    (Pen-Test)
  • Re: Anonymizing Packets yet ensuring 0 % packet loss
    ... exercise of mine is to by pass the security systems in place & prove ... you need anything that needs a reply from the network, ... We do not want the administration to say that " we could have stopped ... enumerate the services, administration subnets, department subnets, ...
    (Security-Basics)