<Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (February 2012) (Learn how and when to remove this template message) </Td> </Tr> <P> In computer networking, IP address spoofing or IP spoofing is the creation of Internet Protocol (IP) packets with a false source IP address, for the purpose of hiding the identity of the sender or impersonating another computing system . One technique which a sender may use to maintain anonymity is to use a proxy server . </P> <P> The basic protocol for sending data over the Internet network and many other computer networks is the Internet Protocol (IP). The protocol specifies that each IP packet must have a header which contains, among other things, the IP address of the sender of the packet . The source IP address is normally the address that the packet was sent from, but the sender's address in the header can be altered, so that to the recipient it appears that the packet came from another source . The protocol requires the receiving computer to send back a response to the source address, so that spoofing is mainly used when the sender can anticipate the network response or does not care about the response . </P> <P> IP spoofing involving the use of a trusted IP address can be used by network intruders to overcome network security measures, such as authentication based on IP addresses . This type of attack is most effective where trust relationships exist between machines . For example, it is common on some corporate networks to have internal systems trust each other, so that users can log in without a username or password provided they are connecting from another machine on the internal network (and so must already be logged in). By spoofing a connection from a trusted machine, an attacker on the same network may be able to access the target machine without authentication . </P>

What is the difference between an ip packet and an ip address