Given the ip address and subnet mask 192.168.10.0 and255.255.255.224
a) what is the maximum number of subnets in the network?
b) what is the number of hosts?
c) what are the valid subnets?
it is requested pls. give details how u have calculated?

a) Maximum subnets=8

b) if there is no subnet , no. of hosts will be 32-2 = 30. If there are 8 subnets as above, then no. of hosts will b 4-2=2.

c)  Valid subnets are  6

                         192.168.10.32          

                         192.168.10.64                    

                         192.168.10.96

                         192.168.10.128

                         192.168.10.160

                         192.168.10.192

Explanation:

a) Maximum number of sub nets in the network

    For number of sub nets in a network , which class this ip address belongs to

         IP address  192.168.10.0

         subnet mask 255.255.255.224

192 in ip address means it is a class C address.

In class C address -

Network address-24 bits

Host address-8bits

For number of subnets we check last block of subnet mask.

224 -covert this into binary

                11100000

From binary form ,we can conclude that 3 bits are used for sub network as only 3 are 1.

  =2^n

  = 2^3 =8  

b)  Number of hosts

In a network,

     Number of hosts is (2^host no -2)

We have subtracted 2 because out of these hosts two are used in broadcasting and other purposes.  

Host number is equal to the 0's in the Subnet mask

                     255.255.255.224

convert this into binary number i.e

   11111111.11111111.11111111.11100000

So,5 0's are there

           Number of valid hosts= 2^5 -2

                                                = 32-2

                                                =  30

c) The Valid subnets are

For valid we have to perform Logical AND with IP Address and subnet    mask.

       IP address  192.168.10.0

       subnet mask 255.255.255.224

    Convert these in binary -

IP address  11000000.10101000.00001010.00000000

Subnet mask  11111111.11111111.11111111.11100000

after performing And operation- 11000000.10101000.00001010.00000000

                192.168.10.0

           this is the host address

                 192.168.10.224 this is the broadcast address

    These are the valid sub nets

                         192.168.10.32          

                         192.168.10.64                    

                         192.168.10.96

                         192.168.10.128

                         192.168.10.160

                         192.168.10.192

answer; always; never;