enggfarooq

 Profile Answers by enggfarooq 

• Mar 19th, 2007

 

Dividing a big network into multiple small networks for our efficiency is called subnetting.
there is an formula to calculate.
for ex:if u have an address 196.152.10.0
this is an class c address
my requirement is i want 4 subnets.
ths formula is 2^n-2=subnets (2 to power n )
where n is the number of subnets
u know that 3 bytes r network ids and 1 byte is for host
write down the last byte in binary
                           
 128    64     32     16       8       4      2     1
  0        0       0        0       0       0      0     0

burrow the bits from host byte from left to right

2^3-2=8-2=6 subnets
our requirement is for 4 subnets.
we r getting 6 subnets no problem if ur netowrk grows then the remaining subnets will be used
so now ur first subnet starts from
196.152.10.33 to 196.152.10.62, 196.152.10.32 is ur network address and 196.152.10.63 is ur broadcast address
the next subnet is 196.152.10.65 to 196.152.10.94
196.152.10.64 is ur network address and 196.152.10.95 is ur broadcast address
the 3rd subnet wii start from 196.152.10.97 to 196.152.10.126
196.152.10.96.is ur network address and 196.152.10.127 is ur broadcast address
and the fourth subnet is 196.152.10.129 to 196.152.10.158
196.152.10.128 is ur network address and 196.152.10.159 is ur broadcast address
  this is my requirement still i will get another 2 subnets
196.152.10.161  to   196.152.10.190
 
196.152.10.192   to   196.152.10.223


and the subnet mask for all my subnets will be add the bits which u have made use to make the subnets i;e: 128+64+32=224

and finally the subnet mask for all subnets will be 255.255.255.224
got it guys.