Cant wrap my head around supernetting

First post on the site, although i have used the site in the past to help me pass the A+ exams, so thanks to the powers that be for that.
I live in BC, Canada and im attending the BC Institute of Technology; I am taking a couse as part of a network administrator technician associate certificate. The course is Understanding TCP/IP, and we have just covered supernetting, which I understand is the same as CIDR although the instructor never made that too clear.
So the reason for the post is that we were just given an assignment involving supernetting and the text book is not too helpful to work out the problems. I am wondering if anyone knows some good resources to help work out supernetting problems

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Plantwiz

Do you understand subnetting?
This may be helpful: http://www.learntosubnet.com/

Otherwise maybe this for supernetting?
http://www.tcpipguide.com/free/t_IPSupernettingClasslessInterDomainRoutingCIDRHiera.htm

Kevin J Williams

Thanks Plantwiz,
I think i may be thinking too much about it, but i dont want to(read: can't-OCD

) move past it until i understand it. Good thing the assignment isnt due until the 24th.
I have gone through the learntosubnet.com tutorial and although i am new to the subnetting thing i do understand the concepts. I am reading through the TCP/IP Guide info. as i write this, so thanks for the input.
The problems we are being asked to solve are to state what the network address, prefix, directed broadcast, and the range for 8 addresses supernetted.
I think i have it worked out that i need to borrow 3 bits from the network side and then adjust the prefix based on that, then the broadcast address will be the last address available of the last IP address (of the 8 original addresses); then the range would be from the first address, not including the directed network address, to the last address not including the broadcast address.
What do you think?

EdTheLad

For 8 addresses you would need 4 bits as 3 bits give (2^3)-2 = 6 , to learn this, your best bet is to get solid at subnetting first and then learn how to create a summary address and finally learn supernetting.
To do this quickly,go to the search function on this site and search the ccna forum for each term i gave.There are loads of explanations there and i'm sure you just need one to click.

netcom2000

Know how you feel, I am just about to start the chapter on VLSM's (Variable length subnet masks) and think I will struggle with subnetting, anyway for now, you dont need to know how to subnet, just knowing why you would be needed to use them and what they are, you wont get many, if any questions on Subnetting for the Network + exam, if this is what you arre going to be taking soon.

Just understand what a network ID, SubnetID and hosts ID is and know your classes, C, B and A, and the other two D and E, and you should be fine.

If you are planning to go for the CCNA exam after network + try to obtain the Sybex book on exam 640-801 CCNA

sthomas

Just understand what a network ID, SubnetID and hosts ID is and know your classes, C, B and A, and the other two D and E, and you should be fine.

This is all you need to know about subnetting to pass the exam, at least when I took it 4+ years ago. Of course the exam has changed since then. And what you need to know about subnetting to be a Network Tech/Admin is another story.

Kevin J Williams

Thank you all for the input, it really is appreciated.
I have been in the IT field for 6 months (although in a limited role managing a help desk) and even now i look back at the things i was struggling with, and shake my head at how simple the solutions now seem. In fact, i do realize that in my post i used some terms incorrectly, and I probably posted this in the wrong forum.

I am not actually training for the Net+ exams, but a college equivalent. Call me crazy, I should be taking the Net+ cert. but my employer is paying for it, so i'll take it.
I know that before too long that this particular problem/struggle will seem small and simple compared to the challenges that lie ahead when i start doing the "real" IT work.
Just as an update i have since been able to answer my original question, using the info. that i recieved from all of your answers, and am confident that i understand the concepts involved.
Like all of you, I am sure have experienced, the amount of information to absorb is sometimes a daunting task, but having the tools/skills/weapons available to me at the end of the day is what keeps me going. Oh yeah, and the possibility of a fat pay cheque.

Kevin J Williams

EdTheLad wrote:

For 8 addresses you would need 4 bits as 3 bits give (2^3)-2 = 6 ,

HI Ed, thanks for the input. Wouldn't this only apply to subnetting where you must not include the network address and the broadcast address in the number of available (valid?) addresses?

EdTheLad

Kevin J Williams wrote:

EdTheLad wrote:

For 8 addresses you would need 4 bits as 3 bits give (2^3)-2 = 6 ,

HI Ed, thanks for the input. Wouldn't this only apply to subnetting where you must not include the network address and the broadcast address in the number of available (valid?) addresses?

Yep, but i blame the bad wording of the question

Kevin J Williams

Dear EdTheLad,
touche!