Subnetting

B

blando233

Member
Hey guys so i am having a problem learning how to subnet my teacher sucks and doesnt teach it at all he showed like a 5 min review over it and i dont understand how to subnet at all so i was wondering if anyone knows a simple easy way to learn how to subnet any examples anything. Thanks guys
 
Well idc what example really just want to atleast understand how to subnet doesnt like matter like whatever IP or what not just want to understand how to do it and see if there are easy ways to subnet
 
Well, an example shows you how to do it. but lets give it a whirl without an example then.

As you know there are 4 classes but just 3 that are used: A, B and C
A is from 1.0.0.0 to 127.0.0.0
B is from 128.0.0.0 to 191.0.0.0
C is from 192.0.0.0 to 223.0.0.0

For class A the first octet is the network portion and the other three octets are for the hosts.
For class B the first 2 octets is the network portion and the remaining two are for hosts.
For class C the first 3 octets is for the network portion and the last one is the host portion.

The reason why we subnet is not to waste ip addresses.
For example: say we have this address 192.16.1.0 with a subnet mask of 255.255.255.0 with this address we can have 256 hosts in that network. but we only need 24 hosts actually. it would be a waste to assign that address there and then there would be 236 addresses left that are going to waste. so we subnet.

here is a chart that we can use to figure out what subnet to do this into:
http://area51services.com/information/subnet_mask/IP-class-classless-subnet-chart.jpg

now we have 24 hosts and we are in class C so we take a look at the chart and match up the subnet with the number of hosts. the 255.255.255.224 mask matches our requirements since it can accommodate 32 hosts.
so there we go: we then just write there 192.16.1.0/27 to say that we have subnetted this to the mask of 255.255.255.224.
 
AHHHH ok ok i see i see but oneee question i understand everything so far but how did u get the 224 in the 255.255.255.224 lost where you got that and thanks for the chart also :)
 
its in the chart. if you look at the number of hosts. 32 on the left you will see the subnet mask 255.255.255.224

i hate to do this but i want to :P
this is the most basic of all subnetting wait till you start doing VLSM :)
 
another way you can understand this is by doing binary.

11111111.11111111.11111111.00000000 is the 255.255.255.0 subnet. now just add ones to the last octet until you get 224 there.
 
ahhh ok i see i see now lol duhhh :P thanks alot man deff helped me out alot by any chance u kno much about hard drives?
 
cbt nuggets icnd1

great tutorial on subnettibg on this course if you join or find it online:cool:
 
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