IP Address & Subnetting

IP Address (Internet Protocol Address or often abbreviated IP) is a row of binary digits between 32-bit to 128-bits are used as an identification address for each host computer in a network the Internet. The length of this figure is 32-bit (for IPv4 or IP version 4), and 128-bit (for IPv6 or IP version 6) which indicates the address of the computer on the Internet network based TCP / IP.

IP addresses can be separated into two parts, namely the network (net ID) and the host (host ID). Net ID instrumental in the identification of a network from another network, while the host ID serves to identify a host within a network. Thus, all hosts are connected in the same network have the same net ID. Some of the bits of the early part of the IP Address is the network bits / network number, while the rest is for the host. The dividing line between the network and hosts are not fixed, depending on the class network. IP addresses are divided into five classes, namely class A, class B, class C, class D and class E.

Determination of the class is done in the following ways:

The structure of class A IP Address :

Class A IP address is 0, with a length of 8 bits net ID and host ID 24 bits long. So the first byte of the IP address class A has a range of 0-127. So in class A there are 127 networks with each network can accommodate about 16 million hosts (255x255x255). Class A IP address given to the network with a very large number of hosts.


The structure of class B IP Address :

Class B IP address bits are always set to 10 so the first byte is always a value between 128-191. Network ID is the first 16 bits and 16 bits are the host ID so that if any computer has the IP address 167.205.26.161, the network ID and host ID = 167 205 = 26 161. On. Class B IP address has IP range from 128.0.xxx.xxx to 191.155.xxx.xxx, which amounted to 65 255 network by the number of hosts per network host 255 x 255 or about 65 thousand hosts.

The structure of class C IP Address

Class C IP address originally used for small networks such as LANs. The first three bits of a class C IP address is always set to 111. Network ID consists of 24 bits and 8 bits of remaining host ID so it can be formed about 2 million networks with each network has 256 hosts.


Class D and E are not used in general, a class D is used for multicast network, the first 4 bits of the class D IP address is always set 1110 so the first byte ranges between 224-247, while the next bit is set as necessary multicast group.
The structure of class D IP Address

Class E for experimental keprluan, class E IP address is not made available for public use. The first four bits of the IP address of this class is set 1111 so the first byte ranges between 248-255.
The structure of class E IP Address :

Network addresses used by routers to find a place a local computer network is located, while address local computer is used to identify a computer on the local network.
IP version 4 (IPv4 address is often called) is a type of network addressing that is used in network protocol TCP / IP using the IP protocol version 4. Total length is 32-bits, and can theoretically address on a host computer up to 4 billion or more precisely 4,294,967,296 hosts around the world, the number of hosts was obtained from 256 (obtained from 8 bits) dipangkat 4 (because there are 4 octets) so that the value maximum of alamt IP version 4 is 255.255.255.255 where the value is calculated from zero so that the value of the host that can be accommodated is 256x256x256x256 = 4,294,967,296 hosts. so that when a host of global quota then be made exceed the IP version 6 or IPv6.
Examples of version 4 IP address is 192.168.0.3


SUBNETTING

we have to master the concept of subnetting to get new IP address, which in this way we can create a new network ID of a network that we had before. Subnetting is use to break up a single network into several smaller networks. To reproduce the network ID of an existing network id, where the host ID sacrificed in part for use in making additional ID

Remember the formula to find a lot of subnets is 2 n - 2
N = number of bits that are shrouded in

And the formula to find number of hosts per subnet is 2 m - 2
M = number of bits that have not been shrouded in

Examples of cases with the completion of I:
Ip address 130.200.0.0 with a subnet mask of 255.255.224.0 identified as class B.
Subnet mask: 11111111.11111111.11100000.00000000
3 bits of the octet to 3 have been used, tingal 5 bits that have not been shrouded in so many groups of subnets that can be used is a multiple of 2 5 = 32 (256-224 = 32)
32 64 96 128 160 192 224

So the IP group that can be used dalah;
loopback subnet  130.200.0.0 - 130.200.31.254
130.200.32.1 - 130.200.63.254
130.200.64.1 - 130.200.95.254
130.200.96.1 - 130 200 127 254
130.200.128.1 - 130 200 159 254
130.200.160.1 - 130 200 191 254
130.200.192.1 - 130 200 223 254

Case:
An emerging company has many branches and each branch office has 255 workstations, network address is 164.10.0.0 available, create a subnet with the largest number of subnets

Settlement; 164.10.0.0 is in class B, meaning octet 3 and 4 are used for the host, whereas a branch office there are 254 hosts, then take a bit longer than the third octet so pretty.

So the new subnetmask
11111111.11111111.11111110.00000000
255. 255. 254. 0

Subnet that is available is 256-254 = 2, then the subnet multiples of 2 up to 254.
The number of subnets (2 7-2) = 128-2 = 26 subnets
The number of hosts / subnet (2 9-2) = 512-2 = 510 hosts
164.10.0.0 to 164.10.1.0  discarded
164.10.2 .1 to 164.10.3.254
164.10.4.1 to 164.10.5.254
164.10.6.1 to 164.10.7.254
164.10.8.1 to 164.10.9.254
164.10.252.1 to 164.10.253.254

Examples of practice subnetting: class B address

Network address 172.16.0.0 and the subnet mask of 255.255.192.0

Subnet 192 = 11 million, 2 2-2 = 2
Host 2 14 - 2 = 16 382 (6 bits in the third octet, and 8 bits in the fourth octet)
Valid subnet 256-192 = 64. 64 + 64 = 128

Subnet 64.0 128.0
The first host 64.1 128.1
Last Host 127 254 192 254
Broadcast 127 255 199 255

Description, then the 172.16.64.0 subnet or 64.0, 64.1 or have first host 172.16.64.1 to 171.16.127.254 and 172.16.127.255 broadcastnya address


Examples of practice subnetting: class A address

Network address 10.0.0.0 and subnet mask 255.255.0.0

Subnet 255 = 11111111, 2 8-2 = 254
Host 2 16 - 2 = 65 534
Valid subnet 256-255 = 1, 2, 3 and so on. (all in second octet). Subnet to be 10.1.0.0, 10.2.0.0, 10.3.0.0 and so on until 10.254.0.0

Subnet 10.1.0.0 10.254.0.0 ...
The first host 10.254.0.1 10.1.0.1 ...
Last Host 10.1.255.254 ... 10,254,255,254
Broadcast 10.1.255.255 ... 10,254,255,255