The network administrator is needed to understand Subneting in network implementation. Subneting used to economize on the IP range. In addition Subnating also used for computer network security by limiting the number of IP addresses that can be used on a computer or host.
Why subneting need to be used to economize on the IP and network security? Because the range of a network, as an example of class C (remember the first tutorial) has a host range or number as many as 254 in one network. This is very inefficient if used for small networks that require a smaller number of computers. Subneting then used to minimize the number of networks to save digunkaan IP also. If you have receipts Subnating it was out of a full class and then called with less class.
For example:
1. 192.168.1.2 / 26
- To find subnetmask:
Notice / 26 is called the network previk, meaning binary 1 on the total number of 26 and 32 bit binary 0 numbered six.
Binary 11111111 11111111 11111111 11000000
Decimal 255 255 255 192
So it is subnetmask: 255 255 255 192
- To find the number of hosts:
The calculations to find the number of hosts is by using the formula:
Sh = 2n-2
Description formulas
Sh = Number of hosts in one network
n = number of binary 0 in the netmask
-2 = Less 2 because there are two IP that should not be used because it is used for IP hosts and IP Broadcast Network.
Given: n = 6 (corresponding to the example above)
Sh = 2n-2
= 26-2
= 64-2
= 62
So the number of hosts to 192.168.1.2 / 26 is the 62 host
- Here's the IP that is used:
Network 1:
192.168.1.0 (should not be used because the IP Network)
192.168.1.1 to 192.168.1.62 (the IP range is used as a host)
192.168.1.63 (may not be used because the IP Broadcast)
Network 2:
192.168.1.64 (may not be used because the IP Network)
192.168.1.65 to 192.168.1.126 (the IP range is used as a host)
192.168.1.127 (should not be used because the IP Broadcast)
And so on ....
2. 202.10.10.3 / 30
- To find subnetmask:
/ 30 when arranged in binary:
Binary 11111111 11111111 11111111 11111100
Decimal 255 255 255 252
So it is subnetmask: 255 255 255 252
- To find the number of hosts:
Note: n = 2 (corresponding to the example number 2)
Sh = 2n-2
= 22-2
= 4-2
= 2
So the number of hosts for the 202.10.10.3 / 30 is the second host.
- Here's the IP in use:
Network 1:
202.10.10.0 (may not be used because the IP Network)
202.10.10.1 to 202.10.10.2 (the IP range is used as a host)
202.10.10.3 (may not be used because the IP Broadcast)
Network 2:
202.10.10.4 (may not be used because the IP Network)
202.10.10.5 to 202.10.10.6 (the IP range is used as a host)
202.10.10.7 (may not be used because the IP Broadcast)
And so on ....
From the two examples above actually comes from a class C, but later in subneting. In class C, there were 254 hosts, while after dilakuakan subneting then the number of hosts would be minimized, with the network previk / 26 the number of hosts to 62 hosts with the network while previk / 30 the number of host to two hosts only. You can do subnating accordance with the number of host computers or the amount you need.
Hopefully useful
