1. Indirizzo IP – An IP address is an identifier assigned to each computer and other device connected to a TCP/IP network that is used to locate and identify the node in communications with other nodes on the network. IP addresses are written and displayed in human-readable notations, such as 172.16.254.1 in IPv4. Version 4 of the Internet Protocol defines an IP address as a 32-bit number and its deployment commenced in the mid-2000s and is ongoing. Addresses have been distributed by IANA to the RIRs in blocks of approximately 16.8 million addresses each, each ISP or private network administrator assigns an IP address to each device connected to its network. Such assignments may be on a static or dynamic basis, depending on its software, 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, the header of each IP packet sent over the Internet must contain the IP address of both the destination server or website and of the sender. The Domain Name System translates domain names to the corresponding destination IP address, both the source address and the destination address may be changed in transit by a network address translation device. The senders IP address is available to the server and becomes the destination address when the server responds to a client request. A sender wanting to remain anonymous to the server may use a proxy server, when the destination server responds to the proxy server, it would forward it on to the true client—ie. Change the IP address to that of the originator of the request, a reverse DNS lookup involves the querying of DNS to determine the domain name associated with an IP address. There are two versions of the Internet Protocol, IP version 4 and IP version 6, each version defines an IP address differently. Because of its prevalence, the generic term IP address typically still refers to the addresses defined by IPv4. The gap in version sequence between IPv4 and IPv6 resulted from the assignment of number 5 to the experimental Internet Stream Protocol in 1979, an IP address in IPv4 is 32-bits in size, which limits the address space to 4294967296 IP addresses. Of this number, IPv4 reserves some addresses for special purposes such as private networks or multicast addresses. IPv4 addresses are usually represented in dot-decimal notation, consisting of four numbers, each ranging from 0 to 255, separated by dots. Each part represents a group of 8 bits of the address, in some cases of technical writing, IPv4 addresses may be presented in various hexadecimal, octal, or binary representations. In the early stages of development of the Internet Protocol, network administrators interpreted an IP address in two parts, network number portion and host number portionIndirizzo IP – Decomposition of an IPv4 address from dot-decimal notation to its binary value.
2. Regional Internet Registry – A regional Internet registry is an organization that manages the allocation and registration of Internet number resources within a particular region of the world. Internet number resources include IP addresses and autonomous system numbers, collectively, the RIRs participate in the Number Resource Organization, formed as a body to represent their collective interests, undertake joint activities, and coordinate their activities globally. The Number Resource Organization is an organization uniting the five RIRs. AFRINIC, which was created in April 2005, joined on April 25,2005. Country code top-level domain Geolocation software Internet governance Local Internet registry National Internet registryRegional Internet Registry – Regional Internet Registry