help me how to subnet class A, B & C

yea dove!! thanks i already knew this concept...while i was just playing with this subnetting. but i didn't know that automatecally i introduced to the new concept!!

Yawn......

Righty, durk21, going back to your very first post, we were high lighting that the first and last HostIDs of all 0s' and all 1's are usable in some vendors implementations of their TCP/IP stacks.

The first post had on the bottom;

Also on a side note 255.255.0.0 falls under CLASS A but for right now we will call it a class B to simply show the math. The first Class B subnet is 255.255.128.0

This is where these last 3 pages or so came from. How you can make such a statement when the subnets are;

Class A = 255.0.0.0
Class B = 255.255.0.0
Class C = 255.255.255.0

is what we are going on about. This is Classfull subnets since these are the default subnets for these classes. In the older days (before me) the subnet didn't really exist as the first octects first bits were used to determine its class. When people wanted to start further manipulating the number of networks/hosts the subnet mask came into the equation, VLSM.

Back to the above statement, 255.255.128.0 is a Class B (255.255.0.0) and you are further deviding it down using the third octect which is VLSM (well thats what i thought was VLSM).

Unless i am missing something over the past 3 pages then this is pretty much what this was all about, hmmm i think ? lol.

FROM WHAT CISCO HAS EXPLAINED TO ME

255.255.0.0

IS THE LAST RANGE IS A CLASS A SUBNET when not using VLSM

Quote:
Also on a side note 255.255.0.0 falls under CLASS A but for right now we will call it a class B to simply show the math. The first Class B subnet is 255.255.128.0


This is where these last 3 pages or so came from. How you can make such a statement when the subnets are;

Class A = 255.0.0.0
Class B = 255.255.0.0
Class C = 255.255.255.0

is what we are going on about. This is Classfull subnets since these are the default subnets for these classes. In the older days (before me) the subnet didn't really exist as the first octects first bits were used to determine its class. When people wanted to start further manipulating the number of networks/hosts the subnet mask came into the equation, VLSM.

Back to the above statement, 255.255.128.0 is a Class B (255.255.0.0) and you are further deviding it down using the third octect which is VLSM (well thats what i thought was VLSM).

Unless i am missing something over the past 3 pages then this is pretty much what this was all about, hmmm i think ? lol.

Ok then, i'm tired of disagreeing.

Think i will stick to my own way because what you are saying just doesn't make any sense unless i am missing something

Anyhow, enjoy the rest of your stay

Wayne

you are missing something bc its not something i can explain i just know it works i dont argue it just works ive used it in labs and this is how the teachers have explained it so i just use it.

well durk21,
i am completely agree with Smurf...! you can say that 255.255.0.0 is the last range of subnet mask for class A. but not last subnet.

its possible that last subnet of class A is 126.255.0.0
but 255.255.0.0 is impossible for class A subnet.

if you say 255.255.0.0 is a subnet. then it will be a subnet of class E.


because for class A network/sub-network or for Class A IP address
first bit of first octet must be 0. so maximum number possible with first bit as 0 is 128. so subnet can take any no between 1 to (128-2=)126

i guess you got the point!