Unanswered Question
Jun 19th, 2007

Using a subnet mask of, which of the IP addresses below can you

assign to the hosts on this subnet? (Select all that apply)






The answer to this question is C,D,E

Now why would we need to subnet a private IP address (option E).

I have this problem too.
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Overall Rating: 3.5 (8 ratings)
mohammedmahmoud Wed, 06/20/2007 - 00:20


We can subnet any IP address space with no constrains (whether it is private or public), why would we do that, practically speaking it is simply for example if a corporate needs to assign 1 class (private addresses) to a branch and this branch consists of 2 LANs each with a max of 10 users, then it would be perfect to assign the LAN a single class C and assign half of it to a LAN and the other half to the other LAN.


Mohammed Mahmoud.

jrensink78 Thu, 06/21/2007 - 08:19

In all honesty, I don't think you'd really see a private address space subnetted beyond very often. But maybe you'll have a network administrator that wants to be really efficient with their IP addressing scheme.

Or, if your company is part of a larger corporate network, it may be harder to get the permission to add a new class C address space to your network. So it might be easier to split up one of your current class C networks to reach your goals.

Wilson Samuel Thu, 06/21/2007 - 08:48

>Now why would we need to subnet a private IP address (option E).

If thats your only question, then the answe to the question would be simply the same reason for which we subnet a Public IP Address.

Subnetting actually has nothing to do with Private or Public, its just subnetting.

Secondly, Private Address range is or equvivalent to a Class B which means it would be having 65535 hosts which is practically meaningless unless we subnet it.

Hope that helps,

Please rate if it helps.


Wilson sAmuel

nirmalsoni Thu, 06/21/2007 - 23:51

Well why we actually subnet is we utilize a better solution for utilizing our ip addresses.As you might have come across that along serial links we use a mask of /30 to get along ..why its just utilizing ip addresses more efficiently giving only two usable addresses links along connecting each other going without wasting it..

Now if u have certain number of hosts on the segment lets say 25..why would u allocate a mask that would yield more than 100 users except that all addresses used get wasted, in case if u dont have much for future growth

Thats why we do subnet when ever we want effective utilization of ip address..does not matter if its a private addresses

ravishankar.ipv6 Sat, 08/04/2007 - 02:18

ok so u want to know why do v need to subnet

a private address.....

take a case study wen u r having 4 department n u need some 25 hosts in each deptt.....

v can assign 4 diff n/ws and their corresponding hosts.....


and in each subnetwork we can have at the most 30 hosts....

of wich the host add belongs to the subnetwork

ok ru satisfied with this answer.....

if u r not good in subnets ........ i will help u ......... so let me know ue feedback


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