Subneting

[BVR]

I just don't seem to understand how does subnetting work. The part where you borrow from one octed to another, or fool the PC to think that you are a level C address while realy you are only level B. Can someone please explain it in a nutshell I am planning to take certification on net+ after holidays.

[chesman]

ok, well i spent about 2 months subnetting this semester before i, or anyone else in the calss understood it, so first of all i think you should go study it a bit. lol



But, ok, let me see if i can do it


ok thre are 3 main subnet masks u use, 255.0.0.0, 255.255.0.0, and 255.255.255.0

besides these three, there are two toher class d, and class e, where class d is used only in test enviroment s really and those ips never reach the internet. the E class address's are used mainly for broadcasts and stuff, cant REALY remmember exactly, but you wont se these around. and those last two does not have a 255 mask to their own either.


ok on to the acual subnetting, ill send you a chart i use. ill add it as a file.

what ever you are going to subnet depends on either how many hosts you want, per subnet or how man y subnets you want per netowrk, and you can decide this from the chart.


ok, wel it is christmas morning, and well i am oging to go enjoy it, so i dont really have time to explain this fully, so i will try to find something for you and help you out moreso later, PM me and ill gladly help



Ches
Have a Great Christmas!!!

[BVR]

Well i've just finishe net+ course, but you know the jerk of a teacher planned to spend 3 days on TCP/IP originally & by the end he ended up spiting it out on the last dayin two hours. I've been studying on my own though & I seem to be getting it to stick. Thanks for your help any info you can provide is apriciated.

[mikesgroovin]

That doesn't sound like a very good teacher.
Subnetting is, in my opinion, the most difficult thing to understand. Some people just "get it". While others, may get it eventually, but it's until the person explaining it, explains the process in one specific way...then the student all the sudden does a "Oh Yea!!!! I get it" sort of acknowledgment.
In the Cisco academy, we were on subnetting for about 3 straight classes! Fortunatly, my father was the instructor and I am well-attuned to how he teaches, so I was able to understand it right away. But, at one point in the 3rd class, my father sat down in front of the class and said "There are a few that still don't understand this, so instead of me trying to explain this in the various ways that I have been already, I'll take any volunteers...."
So, another student and I got up and pitched in. It was a matter of just teaching it in a way that the others could relate.
This is one area where I feel, if you don't know it....then don't continue studying networking until you do..
I was just trying to find a resource online where I felt it was explained pretty well and simplistically.

Here is a pretty good one but you have to know a little binary...If you at the point of subnetting...you should be WELL beyond binary though...
http://www.ralphb.net/IPSubnet/subnet.html

Hopefully you get a good grasp before your test....good luck!

-Mike

[Harold III]

Let me take volunteer too... ok assume your teacher/exam/whatever tells you to subnet 165.76.0.0 so that you might have 55 subnets, with about 999 computers in each... and you have to give the subnet mask...

in determining the subnetmask, you have to think how can I make up a number that is 2 to the something, and slightly above 55. it's 64. 2^6 is 64. so, you borrow 6 zero bits from 255.255.0.0, with 10 left, 2^10-2 is 1022, 1022>999. so now you have the mask 255.255.252.0

Did I answer your question? probably not.....