Networking - Networking Basics - Discussion

Subnet masks 255.255.255.192 means that it has 6 bits to represent hosts. which means in the last octet: first two bits represent network bits and other 6 host bits.

Now you are looking to fit 192.168.168.188.

Out of two bits you can have : either 10 or 11( 11 is not possible it will go beyond 192) so network bit is 10 , which makes it

128.( 255.255.255.128)

Now , possible values for hosts (for 6 bits) will start with: all zeroes to all 11s( but zero and all ones are meant for this network and broadcast)

Hence the possible values are: from 1 to 62

Which will be: 129 to 190

192.168.168.188 255.255.255.192
mask 26.

And now have to find first address,
Applying AND operation with first address.

192.168.168.188
8 8 8 2

188 = 10111100.
And last 2 bit of mask,
11.

Hence first address,
192.168.168.128.

And last address,

Adding complement of mask into first address.

00000000 00000000 00000000 0011111111.
(63).

Since 1 address 192.168.168.128.

+ 0 0 0 63.

192.168.168.191.

I don't know that how we can find the IP address so please explain in details?

Can anybody explain me this question in more elaborate way from the scratch?

First of all you have to find the base number for that the formula:-.

256-mask = base number will be used.
Now that will be 256-192 = 64.

Now to find the number of valid subnet's do the following.

Subnet 1: 64.
Subnet 2: 64+64 = 128.
Subnet 3: 128+64 = 192 (not valid as it comes upto subnet 's mask address).

So 2 valid subnets.

Next find the broad cast address that would be 127 and 191.

So first and last valid address of the subnet would be.

65, 129 (first valid address).
And
126, 190 (last valid address).

So the range would be 129 to 190.
Hence the answer. :).

I didn't understand, please. Can anyone explain clearly.

To find valid host range, we need subnet mask.

Here subnet mask 255.255.255.192 (11111111.11111111.11111111.1100000).

So for 192 (128+64+0+0+0+0+0+0). Here magic number is 64.

0-63 (192.168.168.0 (n/w address) & 192.168.168.63 (broadcast address). So we shouldn't use as IP address in between we can use these IP addresses).

64-127.
128-191.
192-255.

Our question where 192.168.168.188 address lies in these range?

Answer is 192.168.168.129-192.168.168.190.

I hope you understood well.

Thank you.

Ravi sankar.

I really don't understand these answer correctly. Please explain it in brief.

Please explain other very simple method.

@Ravi Sankar.

Why you call 64 as magic number and why not 192? Please help me.