Subnetting??? Help me!

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I have just started IP addresses, which i understand. I have moved onto subnetting and i dont understand so much........

How much of this do i really need to know and understand right now for 70-271?

I seem to be grasping most of everything else. Is there an easy way to understand subnetting?

I would really appreciate the help....

 

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Spend a couple of hours on the following site and see if that helps..

http://www.learntosubnet.com

 

you do not need to learn how to subnet in the 271 exam. You will need to know the different types of subnet masks are there, and the how to work out which ip class it refers to and vise-a-versa

 

You should probably learn how to subnet anyway as it's a useful skill. It'll certainly be needed for more difficult exams such as the CCNA (if you choose to obtain this when you have the relevant experience).

Qs

 

Yep... and you'll never, ever, ever, ever be able to get away from subnetting. Might as well learn it.

 

Another thumbs up from me for http://www.learntosubnet.com , really helped me understand the whole thing while doing my network+. And you can't knock a great free resource like that!

 

Thanks so much!!!!!

That website is amazing! The penny has dropped!!
I cant believe how quickly i picked things up, now my study book makes sense. OK i dont know how much i'll remember by tomorrow but its a start, and a good one at that!

Thanks again!!!!

 

Yes it is a great help, glad you liked it

 

The way I remember which class an ip address is in (remember this all relates to the first octet)

Firstly we convert binary to decimal (and visa versa) to calculate an octets value

128 64 32 16 8 4 2 1 (bit value)
1 2 3 4 5 6 7 8 (bit number)

each octet (or section of an ip address), is basically 8 bits long, so can be anything from 00000000 or 11111111 or anything in between, for class a imagine

Bit 1 is always 0

ie
00000001 is 1
or
01000000 is 64
or
01111111 is 127 (word of warning, 127 is reserved for loopback so is not used in a network), so this we use to work out

SO Class A always use between 0 and 126 for the first octet

for Class b, the second digit is 0, and the first is always 1

10000000 is 128
or
10100000 is 160
or
10111111 is 191

SO Class b always use between 128 and 191 for the first octet

and for Class C we have the 3rd bit always 0

11000000 is 192
or
11010000 is 208
or
11011111 is 223

224 onwards is used for multicast addresses but this is probably something you dont need to know at the moment.