Subnetting

Post » Sat Feb 19, 2011 2:35 am

After completing my A+ certification a couple months ago, I am going after the CCNA certification now, though we just started learning for the actual test this week in my class.

And subnetting seems fairly easy to me so far but one part of the question that is always asked at the end. Here is an example of a question.

Network Address: 118.0.0.0
Number of needed subnets: 126
Number of usable hosts needed: 131,070

Address Class: A
Default Subnet Mask: 255.0.0.0
Custom Subnet Mask: 255.254.0.0
Total Number of Subnets available: 128
Total Number of host Addresses: 131,072
Number of usable host addresses: 131,070
Number of bits borrowed:

(Actual question time)
For the number of bits borrowed would I place 254 (all of the binary values added up) or just 7 since thats how many places I actually borrowed from?

Thanks for looking over this.
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Lily Something
 
Posts: 3327
Joined: Thu Jun 15, 2006 12:21 pm

Post » Sat Feb 19, 2011 9:03 am

After completing my A+ certification a couple months ago, I am going after the CCNA certification now, though we just started learning for the actual test this week in my class.

And subnetting seems fairly easy to me so far but one part of the question that is always asked at the end. Here is an example of a question.

Network Address: 118.0.0.0
Number of needed subnets: 126
Number of usable hosts needed: 131,070

Address Class: A
Default Subnet Mask: 255.0.0.0
Custom Subnet Mask: 255.254.0.0
Total Number of Subnets available: 128
Total Number of host Addresses: 131,072
Number of usable host addresses: 131,070
Number of bits borrowed:

(Actual question time)
For the number of bits borrowed would I place 254 (all of the binary values added up) or just 7 since thats how many places I actually borrowed from?

Thanks for looking over this.

*digs out CCNA workbook*

Ahh subnetting, easy to do, but with really confusing tables and diagrams in the books.

Its 7, I think.

(note; I won't imagine you'd get asked a question about borrowed bits in the exam, its really just a way to show you whats going on)
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BaNK.RoLL
 
Posts: 3451
Joined: Sun Nov 18, 2007 3:55 pm

Post » Sat Feb 19, 2011 1:17 pm

Ah I see, that is what I thought. It is true that its easy for the most part but the way it is presented makes it seem much more difficult. Thanks for clarifying that.
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Vickey Martinez
 
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Joined: Thu Apr 19, 2007 5:58 am


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