IP Address Classes

1) Static information science address

2) Shared information science address

An information science Address may be a 32-bit range that identifies a pc on the web. each data processor on the web is found not by its name however by its information science address. once somebody varieties the address: WWW.xyz.com it's translated into Associate in Nursing information science address then the pc is directed thereto information science address that is that the data processor.

Now each single web site has Associate in Nursing information science address specifically allotted to that. If each website allotted a separate information science address then there may well be a tangle with running out of information science addresses therefore plenty of the sites on the server use one information science address for multiple sites.

Thus, victimisation quite one website on Associate in Nursing information science address is named a Shared information science address. If a website has its own information science address, and shares with nobody else, it's referred to as a Static information science address. you'll continually access a website that incorporates a static information science address by victimisation its information science address alone, however you can't access a {site|website|web website} employing a shared information science address by typewriting within the information science address alone as a result of once you sort during a shared information science address you hit the server however the server doesn't apprehend that site you're searching for as you have got not told it that name you wish.

Requirement of static informatics address:

1) the most reason to possess a static informatics address for your web site is that, you'll use SSL secret writing on a static informatics address solely. so as to transmit sensitive information over the web, it should be encrypted to stop somebody from intercepting the knowledge.

2) just in case if the positioning required the anonymous file transfer protocol access (anyone will transfer files of the site), the positioning must have a static informatics address.

Other than these 2 reasons there's no want for a web site to possess its own informatics address.

IP Address and informatics categories :

- each host on a TCP/IP network must have a novel address, almost like you needing a novel address for your house. With this distinctive address, it's potential to send information from host to host.

- each packet contains addressing data within the header, and also the informatics address within the header is employed to route packets.

- If many individuals on your street had identical address, the post workplace would have a troublesome time sorting mail. For an identical reason, informatics addresses area unit distinctive on every network.

IP addressing is just configuring every TCP/IP host with a legitimate informatics address : 

For access to the web, a bunch should have AN informatics address that identifies not solely the host address (like a house number) however additionally identifies the network address (like a street number). AN administrator must remember of correct addressing techniques so the hosts on the network can operate properly. TCP/IP addresses area unit supported 32-bit addresses.

IP Address Classes

IP addresses are divided into five IP classes:

IP address class A
IP address class B
IP address class C
IP address class D
IP address class E

All IP addresses are placed in a particular class based on the decimal values of their first octets. In the first octet, an IP address can start with a decimal value between 1 and 255.

IP class A addresses have first octets with a decimal number from 1 to 127. 

Example:
27.x.y.z
102.x.y.z

IP class B addresses have first octets with a decimal number from 128 to 191.

Example:
128.x.y.z
151.x.y.z

IP class C addresses have first octets with a decimal number from 192 to 223.

Example:
192.x.y.z
223.x.y.z

IP class D addresses have decimal values from 224 to 239 in the first octet, and the 4 leftmost bits are 1110.

Example:
224.x.y.z
239.x.y.z

The last IP address class of addresses is IP class E. IP class E addresses range from 240 to 255 in the first octet, and the 4 leftmost bits are 1111. 

Example:
240.x.y.z
255.x.y.z

The system of IP class addresses has been set up to help ensure assignment of unique IP addresses. DHCP discover, DHCP offer, DHCP request, and DHCP acknowledgment are four steps in getting an IP address from a DHCP server.

Computer IP Address Configuration

To find out local what is My IP address and possible TCP/IP networking problem follow next steps:

• If you use win9x/ME go to start-run and type winipcfg, and then press ENTER
• For win2k/xp or vista goes to start-run (Windows Vista user goes to Windows button), type CMD and then ENTER. At the DOS prompt type ipconfig and you'll see DNS suffix, IP address, subnet mask, and default gateway. For more info type ipconfig /all
• For Macintosh select the TCP/IP control panel from the Apple menu's "Control Panels" sub-menu. The TCP/IP control panel window will open and display your IP Address.

IP Address Classes map

Class	1st Octet Decimal Range	1st Octet High Order Bits	Network/Host ID (N=Network, H=Host)	Default Subnet Mask	Number of Networks	Hosts per Network (Usable Addresses)
A	1 – 126*	0	N.H.H.H	255.0.0.0	126 (27 – 2)	16,777,214 (224 – 2)
B	128 – 191	10	N.H.H.H	255.255.0.0	16,382 (214 – 2)	65,534 (216 – 2)
C	192 – 223	110	N.H.H.H	255.255.255.0	2,097,150 (221 – 2)	254 (28 – 2)
D	224 – 239	1110	Reserved for Multicasting
E	240 – 254	1111	Experimental; used for research

Note: Class A addresses 127.0.0.0 to 127.255.255.255 cannot be used and is reserved for loopback and diagnostic functions.

Private IP Addresses