Dear Sam,

IP Address of a computer understand for Internet Protocol. it has been assigned to a computer which has internet facility. this is the logic behind providing IP address to computers.

 IP address

From Wikipedia, the free encyclopedia

An Internet Protocol (IP) address is a numerical label that is assigned to devices participating in a computer network that uses the Internet Protocol for communication between its nodes.^[1] An IP address serves two principal functions: host or network interface identification and location addressing. Its role has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there."^[2]

The designers of TCP/IP defined an IP address as a 32-bit number^[1] and this system, known as Internet Protocol Version 4 or IPv4, is still in use today. However, due to the enormous growth of the Internet and the resulting depletion of available addresses, a new addressing system (IPv6), using 128 bits for the address, was developed in 1995^[3] and last standardized by RFC 2460 in 1998.^[4] Although IP addresses are stored as binary numbers, they are usually displayed in human-readable notations, such as 208.77.188.166 (for IPv4), and 2001:db8:0:1234:0:567:1:1 (for IPv6).

The Internet Protocol also routes data packets between networks; IP addresses specify the locations of the source and destination nodes in the topology of the routing system. For this purpose, some of the bits in an IP address are used to designate a subnetwork. The number of these bits is indicated in CIDR notation, appended to the IP address; e.g., 208.77.188.166/24.

As the development of private networks raised the threat of IPv4 address exhaustion, RFC 1918 set aside a group of private address spaces that may be used by anyone on private networks. They are often used with network address translators to connect to the global public Internet.

The Internet Assigned Numbers Authority (IANA), which manages the IP address space allocations globally, cooperates with five Regional Internet Registries (RIRs) to allocate IP address blocks to Local Internet Registries (Internet service providers) and other entities.

I do agree with Ashotosh

Thanks Raj sir,

I wish to further add, that user of any PC having IP address in the usage of internet can be easily trapped for cyber crimes as it is the basic identity

In the internet age the criminal activities on a computer network are being reconstructed using digital records, IP address assigned to the computer on the network which is its identity acts as being one important digital footprint to trace the criminals. The header & footer of the email often contain the originating IP address of an e-mail message along with a date/time stamp from the servers that handled the message. Now the IP addresses are of two types one is static and other is dynamic which keeps changing and is assigned by the Internet Service Provider (ISP) to the netuser. Thus, the same IP address may be assigned by the ISP to two different netusers in two different times. Many criminals fall in trap because many criminals think that they are anonymous on virtual world which is not so, as you may have seen in past that many persons were caught when they used the cyber café to send threatening emails to political dignitaries. The police traced the culprits through the IP address found in the header of the email and also from MAC address of the computer used by the criminals to send the offending emails. However, the investigating agencies should be careful as the digital evidence are very fragile and sometimes misleading too if not analyzed properly. In the IP address analysis, the time is the key factor. I may quote a para from “International Journal of Digital Evidence” Summer 2002, Volume 1, Issue 2 and I quote:

“Time zone differences are another common source of temporal error in network logs. Some Web servers (e.g., Microsoft IIS) create logs with date/time stamps in GMT and computer systems around the world often use local time in their logs. A failure to correct for time zone offsets can result in a great deal of confusion. For instance, when requesting information from an Internet Service Provider, a time zone discrepancy can cause the ISP to provide the wrong subscriber information and thus possibly implicate an innocent individual.”

Further, the sender of the email may impersonate him to dodge the investigating agencies, for example; “A “ may spoof IP address to create an false impression that email has come from “B”. The criminals very cleverly configure their browsers to connect via a proxy server to conceal their actual IP address and use fake IP address.

Sanjiv has given very good answer.